[Updated at 11 p.m. ET] This post is no longer being updated. For full coverage, check out CNN.com.
[Updated at 10:52 p.m. ET]
About 2,400 homes were damaged in the Oklahoma cities of Moore and Oklahoma City, said Oklahoma Department of Emergency Management spokesman Jerry Lojka. Some 10,000 people were directly impacted by the tornado, he said.
[Updated at 10:43 p.m. ET]
A teacher talks about how she and her students survived the tornado by hiding in a closet and bathroom:
Moore's community center is asking for donations of flashlights, batteries and lanterns for those without power.
There's also a need for tetanus shots, for those who have stepped on nails while working outside.
[Updated at 10:01 p.m. ET]
Teacher Waynel Mayes describes how she had her students "play worms" and sing loudly as the tornado approached.
[Updated at 9:58 p.m. ET]
Moore Fire Chief Gary Bird thanked those first responders who have come from surrounding cities, as well as his own men and women, for helping respond to the tornado and its aftermath.
"We’ve been through several tornadoes, and it’s kind of trial by fire," Bird tells CNN. "(And) we've been very blessed to have all the help."
[Updated at 9:49 p.m. ET]
Gabriel Wheeler described how his teacher at Briarwood Elementary School helped save his and other students lives by putting her hands over children's heads when the ceiling collapsed on top of them.
"It was like the three little pigs, the big bad wolf coming to huff and puff on your house," the teacher, Julie Simon, recalled. "There was this monster coming and we could hear it approaching ... The debris was falling, and we could feel the house was falling across the street. You knew it was coming straight for you."
Gabriel's father, David, says of Simon, "We love her" - a sentiment echoed by his son.
"She helped save my son's life, she helped save othter students' lives, and we're proud of her," David Wheeler said. "She's a member of our family for the rest of our lives."
[Updated at 9:42 p.m. ET]
Country singing star Toby Keith, a native of Moore, tells CNN's Piers Morgan that his sister's house was among those hit by Monday's tornado.
"She gets to keep her stuff, but her house is not livable," Keith says of his sister.
While there's no date, line-up or location set, Keith adds that he's gotten many others from fellow performers to stage a benefit concert for the people of his hometown.
"I’ve had 500 text messages from people all over the music world saying what are we doing, we want to help," he says.
[Updated at 9:34 p.m. ET]
The superintendent of schools in Joplin, Missouri - which was struck by a tornado in 2011 - is expected to fly to Oklahoma on Tuesday night, said Oklahoma state education department spokeswoman Sherry Fair.
Joplin's C.J. Huff is set to discuss the situation in Moore, Oklahoma, with the state education superintendent in that state, Janet Baresi, on Wednesday.
[Updated at 9:31 p.m. ET]
Public schools in Moore, Oklahoma, will be closed for the rest of the year, school district spokeswoman Anna Trowbridge tells CNN. The last day of school was supposed to be Thursday.
[Updated at 9:16 p.m. ET]
A mother describes finding her son - who'd been saved by her day care teacher - in a hospital after the tornado:
[Updated at 9:13 p.m. ET]
Cassandra Jenkins told CNN's Piers Morgan on Tuesday night that she or her relatives still haven't been able to locate her grandparents, Thomas and Claudia Foutch, since the tornado.
Jenkins said her grandparents left a funeral home and were believed to have been heading back to their home in Moore when the twister went through that town. Their home was not affected, but the Foutch's were not in it.
[Updated at 8:56 p.m. ET]
A boy whose school was destroyed talks about his joyful reunion with his neighbor:
[Updated at 8:38 p.m. ET]
Flags will be at half-staff in Oklahoma through early next week:
[Updated at 8:34 p.m. ET]
Oklahoma Gov. Mary Fallin says she's optimistic that Moore and others in her state will recover from the storm, saying, "We're resilient, (and) we believe in helping our neighbors."
"We will come back strong," she told CNN.
[Updated at 8:31 p.m. ET]
A mother recalls taking her toddler, putting him on her lap, then driving as best she could away from the approaching twister:
[Updated at 8:28 p.m. ET]
Moore Mayor Glenn Lewis told CNN's Anderson Cooper on Tuesday night that he didn't expect the death toll will rise past 24, saying, "I think that will stand."
"We feel like we have basically gone from rescue and searching to recovery," Lewis said.
[Updated at 8:21 p.m. ET]
The tornado reduced this 7-Eleven to rubble:
[Updated at 8:19 p.m. ET]
Russian President Vladimir Putin wrote a condolence letter Tuesday to the White House offering sympathy and support after what happened in Oklahoma, a White House official says.
[Updated at 8:13 p.m. ET]
iReporter Swey Boyd describes braving the storm in a truck:
[Updated at 7:56 p.m. ET]
Parts of Mississippi, Tennessee, Arkansas, Louisiana, Texas and Oklahoma were under tornado watches that are set to expire at 10 p.m. (11 p.m. ET).
[Updated at 7:51 p.m. ET]
The tornado gutted what was once a liquor store:
[Updated at 7:49 p.m. ET]
Some 34,000 customers remained without power in Oklahoma on Tuesday evening, reports the Oklahoma Department of Emergency Management.
[Updated at 7:40 p.m. ET]
Janae Hornsby was among those killed at Plaza Woods Elementary School in Moore, her father told CNN's Anderson Cooper.
"Every moment with Janae was Janae's moment," Joshua Hornsby said.
[Updated at 7:38 p.m. ET]
Restaurants are among those donating to the Red Cross and others:
[Updated at 7:30 p.m. ET]
A mental health center will open in Moore to help those affected by the storm, says the Oklahoma Department of Mental Health and Substance Abuse Services. The department also asked that mental health professionals and certified recovery support specialists interested in volunteering their services contact them.
[Updated at 7:11 p.m. ET]
Crediting early warning systems, rescue workers and "the men and women of Oklahoma," Lt. Gov. Todd Lamb told CNN's Erin Burnett on Tuesday evening that "the death toll is small relatively compared to the severity of this storm, the enormity of this storm, and the violence of this storm."
[Updated at 7:03 p.m. ET]
Oklahoma County Sheriff's Office spokesman Mark Myers tweeted this picture of emergency personnel, some with dogs, looking through the rubble:
[Updated at 7:01 p.m. ET]
At the Plaza Towers Elementary School, "You can see that literally the walls are gone, roofs are gone, a lot of structural damage. And you can just imagine what it was like there," FEMA Administrator Craig Fugate told CNN.
He said that, since President Barack Obama signed an emergency declaration Monday night, federal authorities have started to process of registering affected residents for assistance.
[Updated at 6:54 p.m. ET]
A tornado tore this Oklahoma shopping center to shreds:
[Updated at 6:50 p.m. ET]
Many parents were able to get their children out early on Monday from Plaza Towers Elementary School in Moore, Mayor Glenn Lewis said. "Unfortunately, not everybody did," he added.
Plaza Towers was one of two elementary schools hit by the twister. But unlike Plaza Towers, Briarwood Elementary School had no fatalities. It was a "newer model" of schools and had a "safe room" - as is required since a 1999 tornado for newly constructed schools - while Plaza Towers did not, Lewis explained.
[Updated at 6:46 p.m. ET]
President Barack Obama has called Oklahoma's governor "several times" and promised the federal government would do everything in its power to help those affected by the tornado, Gov. Mary Fallin told CNN's Wolf Blitzer.
She said she's also gotten calls and offers of help from Cabinet secretaries as well as "about 25 governors."
[Updated at 6:33 p.m. ET]
Speaking about the tornado rescue and recovery effort in Moore, Oklahoma, Mayor Glenn Lewis said late Tuesday afternoon that "we don't have anybody missing."
[Updated at 6:15 p.m. ET]
Oklahoma Gov. Mary Fallin tweeted that Verizon has taken steps to help in the relief effort:
[Updated at 6:12 p.m. ET]
Fifth-grader Lauryn Fugate talks about how she survived the tornado:
[Updated at 6:09 p.m. ET]
Moore, Oklahoma, resident Billy Verge recalled huddling in a closet with his wife and "the whole house started shaking, shaking, shaking, rocking, shaking for two, three minutes."
"I really didn't think we were going to make it," his wife, Melody Verge, told CNN's Wolf Blitzer. "I just heard it roaring."
[Updated at 5:56 p.m. ET]
What's left of a playground in central Oklahoma:
[Updated at 5:51 p.m. ET]
The city of Moore urged those seeking to help its residents to make "financial donations only, until when and if other types of donations are requested."
The Oklahoma community's government also appealed for volunteers to help with a cemetery clean-up on Wednesday morning.
[Updated at 5:48 p.m. ET]
Oklahoma isn't alone. The National Weather Service reports that trained weather spotters reported a tornado near Copake, New York - a community near where Massachusetts, Connecticut and New York meet - shortly before 5 p.m.
That system was moving east at a 35 mph rate.
[Updated at 5:23 p.m. ET]
Flags stand at half-staff outside Capitol in Washington due to the devastation:
[Updated at 5:21 p.m. ET]
A host of celebrities - many of them with connections to Oklahoma, some even to the hardest-hit areas - are voicing condolences, tributes and messages of strength in the wake of Monday's tornado.
Country singer Reba McEntire - writing from Cape Town, South Africa - said that some of her relatives could hear the rumble from their storm cellar as the twisters passed by about three miles away.
Toby Keith, also a country star, talked about the family and friends he has in Moore, the worst-hit community. "My heart and prayers go to those that have lost so much," the Oklahoma native said. "But Moore is strong and we will persevere."
Actress Alfre Woodard spoke highly of her native state, and urged people everywhere to help.
"I know firsthand the resilience of the people," she said. "They are a community-based culture and will reach their hands out to their neighbors. I trust all Americans will catch that spirit and reach out to Oklahoma now.”
[Updated at 5:07 p.m. ET]
Bad weather remains a problem in Oklahoma, according to a tweet from Will Rogers International Airport:
[Updated at 5 p.m. ET]
A theater's marquee asks for help from above for those impacted in Moore:
[Updated at 4:50 p.m. ET]
Insurance claims will likely top $1 billion, Kelly Collins of the Oklahoma Insurance Department tells CNN. That cost would be higher than that from the May 3, 1999, tornado that hit the same area.
[Updated at 4:49 p.m. ET]
A fund has been established to help those affected by this week's severe weather in Oklahoma - the OK Strong Disaster Relief Fund - Gov. Fallin says. The fund will assist those affected by the May 19 twister near Shawnee and a more powerful one the next day in Moore.
“The generosity of Oklahomans, Americans and people across the world is very encouraging and will help meet many of the short-term needs of victims," Fallin said in a statement. "However, experience tells us there also will be long-term consequences to the challenges victims are facing."
Those wishing to donate can call (405) 236-8441 or go online to unitedwayokc.org.
[Updated at 4:41 p.m. ET]
Diplomats in Geneva, Switzerland, opened a United Nations meeting on disaster risk reduction with expressions of sympathy for those impacted in Oklahoma.
“The impact of this disaster was evident for one of the world’s most economically developed countries," said Deputy Secretary-General Jan Eliasson. "Think how much more dangerous the situation is in places where people are poor and living in fragile homes with insufficient water and health services.”
[Updated at 4:36 p.m. ET]
This map shows the path of Monday's tornado that ripped through central Oklahoma, including key landmarks in and around Moore.
Click here to see the path of destruction.
[Updated at 4:28 p.m. ET]
Damage assessments show that the tornado gained significantly in strength - from an EF0 to EF4 - over a 10-minute span, the National Weather Service reports.
The tornado that hit Moore tornado was 1.3 miles wide, according to the weather service. Its estimated top winds were between 200 and 210 mph, putting it in the EF5 category - the strongest possible for a tornado.
[Updated at 4:12 p.m. ET]
Stephen Eddy, city manager for Moore, told CNN's Jake Tapper that "everyone has been found" who was believed missing because of the devastating twister. He also expressed optimism that his central Oklahoma city would rebound.
"We've been through this before," Eddy said. "We've come back stronger than before every time."
[Updated at 3:58 p.m. ET]
The National Weather Service's Norman, Oklahoma, office offered new details Tuesday afternoon on the strength of the previous day's tornado.
[Updated at 3:47 p.m. ET]
Tributes continue to pour in for those teachers who helped protect children as the tornado barreled through Oklahoma. U.S. Education Secretary Arne Duncan was among those saluting them:
Inspired by the selfless teachers and staff who protected children from harm in Oklahoma.—
Arne Duncan (@arneduncan) May 21, 2013
[Updated at 3:44 p.m. ET]
Moore Mayor Glenn Lewis said authorities there will probably push for even more measures - on top of those already in place - to protect buildings against tornadoes.
He also thanked state and federal authorities for responding speedily, and extensively, in the wake of the devastating tornado.
"They were Johnny-on-the-spot," Lewis told CNN's Anderson Cooper. "And they've sent tons of help."
[Updated at 3:40 p.m. ET]
The Oklahoma City Thunder and its charitable foundation together are donating $1 million to the Red Cross, Salvation Army and other disaster relief organizations to help in the aftermath of this week's tornado.
"We are focusing Thunder resources to help where we can in the relief efforts and to support the organizations that are on the ground assisting those affected by this week’s storms," the NBA team's chairman, Clay Bennett, said. "Even with so much loss, the strength and resiliency of this community have once again been on display, and we will continue to work together as our community and state recover from this disaster.”
The NBA and National Basketball Players Association have also pledged $1 million.
[Updated at 2:50 p.m. ET] The estimated peak wind in the tornado was 190 mph, the National Weather Service said on Tuesday afternoon. That still is a preliminary estimate, according to the weather service. The estimate would make the tornado, as the weather service preliminarily said yesterday, an EF-4 on the Enhanced Fujita scale (meaning it had winds between 166 and 200 mph).
[Updated at 2:34 p.m. ET] Chris Parrish, 22, sent this Vine video to iReport. He told CNN's Nicole Saidi his home was mostly undamaged apart from the roof.
Many other homes in the immediate area were "still standing," he said, but he added: "The other half of the neighborhood is completely flat."
When the alarms went off, he and others took shelter for 20 to 25 minutes, he said. "A few people in our neighborhood had storm cellars and we all gathered in those cellars. Luckily, I don’t think there was anyone from the neighborhood who was injured."
He says a gas leak forced him to spend the night at his brother's house before returning the next day to find a "war zone" awaiting him.
[Updated at 2:12 p.m. ET] The three high schools in the school district of Moore still will have graduation ceremonies on Saturday at the Cox Convention Center in Oklahoma City, Moore Public Schools Superintendent Susan Pierce said Tuesday.
[Updated at 1:50 p.m. ET] More from the news conference: Oklahoma City Mayor Mick Cornett said normal electric service should be restored to the city's Draper Water Treatment Plant soon. Customers should eventually notice normal water pressure, he said. The storm Monday knocked out power to the plant, and authorities, hours later, put the facility on generator power.
[Updated at 1:38 p.m. ET] Back at the news conference: Moore Fire Chief Gary Bird just told reporters that searchers haven't yet examined every structure and vehicle in Moore, but they intend to do so by tonight. And everything will be searched three times before searchers are done with the incident, he said.
[Updated at 1:35 p.m. ET] We're still listening to the news conference, but here's another piece of news that came from elsewhere: Homeland Security Department Secretary Janet Napolitano will travel to Oklahoma on Wednesday to meet with state and local officials "and ensure that first responders are receiving the assistance they need in ongoing response and recovery efforts," the department announced.
The department also noted that Napolitano will travel to Joplin, Missouri, on Wednesday to mark the second anniversary of a devastating tornado there.
[Updated at 1:31 p.m. ET] More from the news conference: Gov. Mary Fallin says the state has established a website where people can get information on services available to people affected by the storm: http://www.ok.gov/okstrong/.
She also said state lawmakers are working on a measure that would allow the state to tap its "rainy day savings account" to create an emergency fund. That fund would be used to, among other things, help local governments fund their services. One example, she said, would be helping communities pay for overtime for emergency responders.
[Updated at 1:23 p.m. ET] Oklahoma officials have just started a news conference – we might get updates on search and recovery efforts.
Gov. Mary Fallin has kicked off the news conference by saying that although Monday's incident was "one of (the) most horrific storms and disasters that this state has ever faced," Oklahoma "will get through this."
"We will overcome. We will rebuild. We will regain our strength," she said.
[Updated at 1:19 p.m. ET] A foundation of Oklahoma City Thunder basketball star Kevin Durant has pledged $1 million to the Red Cross for disaster relief efforts. The Red Cross says it's thankful:
[Updated at 1:14 p.m. ET] CNN's Jake Tapper and Anderson Cooper offer these pictures from the tornado-damaged area:
[Updated at 1:11 p.m. ET] NASA just sent out this image of the storm system that generated Monday's tornado, taken from one of its satellites. The image was taken at 2:40 p.m. CT Monday "as the tornado began its deadly swath," NASA said on its website.
The tornado was on the ground for about 17 miles, the National Weather Service says – starting 4.4 miles west of Newcastle, Oklahoma, and ending 4.8 miles east of Moore, Oklahoma.
[Updated at 12:55 p.m. ET] At least 237 people were injured on Monday in the tornado and storm that devastated central Oklahoma, the state's Office of Emergency Management said Tuesday, citing the Health Department.
At least 24 people were killed in the disaster, an official with the state medical examiner's office said earlier Tuesday.
[Updated at 12:13 p.m. ET] Here's a map showing the path we believe the tornado took on Monday afternoon.
The tornado looks to have gone right over three schools as well as a movie theater. The tornado, preliminarily rated as an EF-4 on the Enhanced Fujita scale (meaning it had winds between 166 and 200 mph), carved a trail as much as 2 miles wide and 22 miles long, officials said.
And we've built an Open Story feature to show images and stories sent in by iReporters from Moore and Newcastle. There are some stunning photos and a map to show exactly where they were taken.
[Updated at 11:46 a.m. ET] Though metro Oklahoma City isn't among the areas facing a severe weather threat Tuesday, it still will face rain and storms today, CNN meteorologist Chad Myers says.
[Updated at 11:36 a.m. ET] Inside First Baptist Church in Moore, the emotion is still very raw – some of the people seeking shelter there are just sitting and crying, says CNN’s Katie Glaeser, who was shown around by a volunteer this morning.
Food, beds and portable toilets are being supplied, and two large-screen TVs are playing the local news, she added.
[Updated at 11:34 a.m. ET] The National Weather Service notes that a tornado watch for parts of southern Oklahoma does not include the Oklahoma City area.
A large portion of the country still is under threat of severe weather Tuesday, from the same storm system behind Monday's twister and several others on Sunday. In the bull's-eye Tuesday are parts of north-central Texas, southeastern Oklahoma, and northern Arkansas and Louisiana, according to the weather service.
[Updated at 11:12 a.m. ET] More details about yesterday's erroneous death toll from officials: Communications problems, including limited cell phone coverage after the storm, might have contributed, Amy Elliott of the Oklahoma Medical Examiner's Office said moments ago.
[Updated at 11:10 a.m. ET] We have a new death toll – lower than before: 24 people have died as a result of Monday's storm, nine of whom were children, according to Amy Elliott of the Oklahoma Medical Examiner's Office.
Previously, the office reported that 51 people had died. Elliott said some of those might have been double-counted.
Seven of the nine dead children were recovered from a school, Elliott said. Many of the victims have been identified and their remains are being returned to their loved ones, she said.
[Posted at 11:01 a.m. ET] An update from CNN's Pamela Brown in Moore:
Some search and rescue teams on a holding pattern as new storm front moves through Moore, OK.—
Pamela Brown (@PamelaBrownCNN) May 21, 2013
The storm system behind Monday's twister and several others on Sunday still is threatening a large swath of the United States on Tuesday, putting 53 million people at risk of severe weather.
[Updated at 10:44 a.m. ET] More from state Rep. Mark McBride, who represents Moore: "If you didn’t have a storm shelter, you didn’t ride it through," because the tornado left little place above ground to hide.
"There was no closet to get into, because there was no closet left,” he told CNN's Chris Cuomo of the tornado that hit Moore on Monday.
[Updated at 10:41 a.m. ET] State Rep. Mark McBride, who represents Moore, told CNN he was "just choking back tears, trying to be strong" while he was with rescue and recovery teams yesterday.
"My family has lived in Moore since the 1940s, and we’ve been through several tornadoes and this is the worst I’ve seen,” he told CNN's Chris Cuomo.
His family is OK. He said his home did not have a shelter and he was now reconsidering that. And he said he was expecting legislation to mandate that schools have shelters.
“People think they can dodge the bullet – it’s hit and miss," he said.
“I don’t think it’s been a priority, but I think after this it will be a priority,” he said of school shelters.
[Updated at 10:22 a.m. ET] Another chunk of what President Obama said at the White House minutes ago – he praised the teachers who shielded children when the tornado came.
"Our gratitude is with teachers who gave their all to shield their children; with the neighbors, first responders and emergency personnel who raced to help as soon as the tornado passed and with all of those who, as darkness fell, searched for survivors through the night," he said.
[Updated at 10:18 a.m. ET] President Obama has finished speaking. Meanwhile, rescuers continue to look for survivors in the Oklahoma City area. As Moore Mayor Glenn Lewis told CNN earlier Tuesday morning, the rescue effort is continuing and "we're very optimistic we might find one or two people."
CNN's Pamela Brown has posted this picture of a search at a leveled bowling alley:
CNN's John King has this panoramic picture of some of the damage in the area:
[Updated at 10:13 a.m. ET] Alluding to Oklahoma's history of dealing with devastating tornadoes – including powerful ones that hit Moore in 1999 and 2003 – President Obama said that if there's hope to hold onto, Oklahomans are better prepared than most.
"Americans from every corner of this country will be right there with them … because we're a nation that stands with" Americans in trouble, he said.
For more on the 1999 tornado that hit Moore, check out this story.
[Updated at 10:10 a.m. ET] More from President Obama's statement at the White House: "Our prayers are with the people of Oklahoma today."
"Oklahoma needs to get everything it needs right away," he said.
[Updated at 10:09 a.m. ET] President Obama is speaking now at the White House:
"One of the most destructive tornadoes in history sliced through the towns of Newcastle and Moore, Oklahoma. In an instant, neighborhoods were destroyed, dozens of people list their lives, many more were injured, and among the victims were children, trying to stake shelter in" the safest place they knew, their school, Obama said.
[Updated at 10:04 a.m. ET] We're expecting President Barack Obama to talk about the Oklahoma disaster from the White House shortly.
[Updated at 9:57 a.m. ET] Out of the 51 deaths initially reported in Monday's tornado, 24 bodies have been transferred to the Oklahoma City Medical Examiner's Office, the agency said Tuesday. An update from the medical examiner was expected at 11 a.m. ET.
[Updated at 9:42 a.m. ET] People in the hard-hit Oklahoma counties of Cleveland, Lincoln, McClain and Pott can start calling FEMA for assistance, Oklahoma Gov. Mary Fallin posted on Twitter.
Wondering how you can help the victims of Oklahoma's tornado disaster? Check this page.
[Updated at 9:30 a.m. ET] Glenn Lewis, the mayor of tornado-ravaged Moore, Oklahoma, told CNN on Tuesday the rescue effort is continuing and "we're very optimistic we might find one or two people."
[Posted at 9:13 a.m. ET] Rescue workers still are scouring rubble for survivors along the miles of destruction that Monday afternoon's massive tornado left in the Oklahoma City area.
Personnel so far have rescued 101 people from wreckage after the tornado chewed up homes and businesses strong>– especially in the Oklahoma City suburb of Moore – and severely damaged a hospital and two elementary schools, authorities say.
The official death toll stood at 51 Tuesday morning, but a coroner's office official said some bodies have yet to be processed by medical examiners – roughly half of them children. And more bodies could be hidden under the vast debris field, authorities warned.
Hundreds of people were injured, officials said.