The five most popular stories on CNN.com in the past 24 hours, according to NewsPulse.
Japan quake live blog: Follow the latest developments since a magnitude 9.0 earthquake hit northern Japan early Friday, triggering tsunamis that caused widespread devastation and crippled a nuclear power plant.
Helicopters dump water on Japan nuclear plant: Helicopters dumped water Thursday on and near the Nos. 3 and 4 units at Japan's Fukushima Daiichi nuclear plant in the latest attempt to halt the nuclear accident that appeared to be spinning out of control. The helicopters belong to the nation's self-defense forces, public broadcaster NHK reported.
'Never give up hope,' Japan's emperor says: Thousands of Japanese filled evacuation shelters or joined foreigners seeking a way out of the country Thursday in the aftermath of last week's devastating earthquake and tsunami.
After disasters comes the exodus from Tokyo: Mid-March is not a high travel season for Japan, but as the nuclear emergency at Fukushima nuclear plant persists, the airports are growing clogged with passengers.
$5 ATM fees coming our way? ATM fees are on the rise at some of the country's biggest banks.
A magnitude 9.0 earthquake hit northern Japan early Friday, triggering tsunamis that caused widespread devastation and crippled a nuclear power plant. Are you in an affected area? Send an iReport. Read the full report on the quake's aftermath and check out our interactive explainer on Japan's damaged nuclear reactors.
[11:55 p.m. ET Wednesday, 12:55 p.m. Thursday in Tokyo] A Tokyo Electric Power company official said Thursday that - based on information gathered from a helicopter that flew over the Fukushima Daiichi nuclear power plant on Wednesday - authorities believe that there is water in a key fuel pool outside one of the plant's most troubled reactors.
"We have been able to confirm that there is water in the spent nuclear fuel pool," the official told reporters about the plant's No. 4 reactor. "But we do not know how much water."
Hours earlier, the head of the U.S. Nuclear Regulatory Commission testified that spent fuel rods in Unit 4 of Japan's stricken Fukushima Daiichi nuclear plant had been exposed, resulting in the emission of "extremely high" levels of radiation.
In addition, authorities announced the number of dead from the 9.0-magnitude earthquake and subsequent tsunami in Japan has risen to 5,178.
As of 10 a.m.Â Thursday (9 p.m. Wednesday ET), 8,606 people were missing and 2,285 were injured, the National Police Agency Emergency Disaster Headquarters said.
[11:05 p.m. ET Wednesday, 12:05 p.m. Thursday in Tokyo] Japanese Defense Minister Toshimi Kitazawa said that he and Prime Minister Naoto Kan decided early Thursday to commence the operation to drop water over the Fukushima Daiichi plant's No. 3 nuclear reactor. They also decided to send water-cannon trucks to the scene to spray water at the No. 3 reactor from the ground.
The plan to drop water from above had been aborted Wednesday, due to concerns about high radiation levels.
"We could not delay the mission any further, therefore we decided to execute it," Kitazawa told reporters.
[10:40 p.m. ET Wednesday, 11:40 a.m. Thursday in Tokyo] Japanese stocks rebounded slightly several hours into trading Thursday. After the Nikkei 225 index opened to a 397-point plunge, the drop was later cut to 204 points, a 2.3% decline.
[10:20 p.m. ET Wednesday, 11:20 a.m. Thursday in Tokyo] Helicopters carrying water made four passes over two nuclear reactors at the Fukushima Daiichi power plant in the first airborne attempts to address overheating. The helicopters, operated by Japan's Self-Defense Forces, have made four passes over the reactors in a span of about 15 minutes around 10 a.m. Thursday. Japanese public broadcaster NHK reported that water was initially dumped on the plant's No. 3 reactor, and then was dumped on the No. 4 reactor. Each helicopter was capable of carrying 7.5 tons of water.
[9:50 p.m. ET Wednesday, 10:50 a.m. Thursday in Tokyo] Nuclear engineers plan Thursday afternoon to begin restoring power to the stricken nuclear complex at Fukushima, a government official said.
"Today, we are trying to restore the power supply using the power lines from outside," said the official with the Nuclear and Industrial Safety Agency. "This is one of the high-priority issues that we have to address."
Once the power supply has been reestablished, then the cooling system will be operated using seawater, he said. He cautioned that the process will not be immediate.
[9:37 p.m. ET Wednesday, 10:37 a.m. Thursday in Tokyo] Water was dropped from helicopters Thursday morning over two nuclear reactors at the Fukushima Daiichi power plant, the first airborne attempts to address overheating inside related to emissions of radioactive material.
The helicopters, which were operated by Japan's Self-Defense Forces, made three passes over the reactors within 10 minutes before 10 a.m. Thursday. In the first two instances, water was dumped on the plant's No. 3 reactor, reported Japanese public broadcaster NHK, with the last being dumped over the No. 4 reactor.
[8:50 p.m. ET Wednesday, 9:50 a.m. Thursday in Tokyo] Temperatures recorded at spent fuel pools at the Fukushima plant Tuesday reached 84.0 degrees Celsius (183 Fahrenheit) at Unit 4; 60.4 degrees C (141 F) at Unit 5 and 58.5 degrees C (137 F) at Unit 6, the International Atomic Energy Agency said.
The agency said on Wednesday that "no data" registered for Unit 4, and Unit 5 had risen to 62.7 degrees C (145 F) and Unit 6 had risen to 60.0 degrees C (140 F). The temperature of these pools is normally kept below 25 degrees Celsius (77 degrees F)
Meanwhile, the United States is sending a radiation detecting aircraft to Japan. The WC-13W Constant Phoenix can detect radioactive clouds in real time, U.S. Air Force officials said.
[8:15 p.m. ET Wednesday, 9:15 a.m. Thursday in Tokyo]Stocks in Japan fell early Thursday morning there amid fears of a nuclear crisis following the nation's catastrophic natural disaster. The Nikkei 225 index, the most prominent measure of stocks traded in Tokyo, was down 397 points, or 4.4%, shortly after the market opened. The index recovered nearly 6% on Wednesday after plunging a combined 16% during the first two trading days following last week's massive earthquake and tsunami.
[7:01 p.m. ET Wednesday, 8:01 a.m. Thursday in Tokyo] As air carriers monitor radiation concerns at Japan's Fukushima Daiichi nuclear power plant, German airline Lufthansa and Italian carrier Alitalia have rerouted flights to and from the Tokyo area to other Japanese airports.
Editor's note: Nancy Grace's new show on HLN, "Nancy Grace: America's Missing," is dedicated to finding 50 people in 50 days. As part of the effort, which relies heavily on audience participation, CNN.com's news blog This Just In will feature the stories of the missing.
This is the 43rd case, and it was shown Wednesday at 9 p.m. on HLN.
Not long after 23-year-old Stacy Peterson disappeared in October 2007, the search became overshadowed by suspicions against her husband, Drew Peterson.
Stacy Peterson was the former officer's fourth wife. They began living together in Bolingbrook, Illinois, while he was going through a contentious divorce from his previous wife, Kathleen Savio. She was later found dead in a bathtub in 2004.
Police have investigated the sites of several remains for Stacy Peterson near the couple's home without success.
Meanwhile, Stacy Peterson's disappearance prompted authorities to reopen the case into Kathleen Savio's death, resulting in murder charges against Drew Peterson in her death. He is awaiting trial, while the families of the two victims await answers and justice.
Workers have been trying to resolve cooling problems at four reactors at northeastern Japanâ€™s Fukushima Daiichi nuclear power plant, whose cooling systems are said to have been disabled by Fridayâ€™s tsunami.Â The crisis has raised serious concerns about radiation.
Below is a short glossary of some terms often used in accounts of the Fukushima Daiichi crisis.
Boiling-water nuclear reactor: The type of nuclear reactor used at the Fukushima Daiichi plant. In these reactors, fuel rods â€“ made of radioactive pellets that usually contain enriched uranium-235 and areÂ encased in zirconium alloy â€“ are placed into a reactor vessel, or large steel tank filled with water. Nuclear fission â€“ the splitting of atoms â€“ is initiated, giving off heat and sending free neutrons toward other atoms, causing more fission in chain reactions. The heat boils the water, which turns to steam. The steam is piped to turbines, making them turn, which creates electricity. A condenser turns the steam back to cool water, which is sent back to the reactor core. See an interactive explaining this reactor type and the Fukushima Daiichi crisis.
Boric acid: A material used to help slow down nuclear fission reactions. South Korea is sending more than 50 tons of boric acid to Japan for use at Tokyo Electric Power's damaged nuclear facilities, Yonhap News Agency reported. South Korea's Ministry of Knowledge Economy said it was supplying the boric acid at Japanâ€™s request after Tokyo used its reserves of the material at the Fukushima Daiichi nuclear plant.
Chernobyl: The site, in northern Ukraine, of the worldâ€™s worst nuclear power plant disaster. A meltdown, explosion and fire at the site on April 26, 1986, sent a large radiation cloud over much of Europe and contaminated large areas of then-Soviet Ukraine, Russia and Belarus. Thousands of deaths are said to be attributed to the disaster, and Ukraine's health ministry estimated that one-sixteenth of its population of 49 million was suffering from grave health disorders related to the incident. The disaster led to thousands of cases of childhood thyroid cancer, according to Dr. Ira Helfand of Physicians for Social Responsibility, which opposes the use of nuclear power.
Hunters in Russia will no longer be allowed to rouse hibernating bears Â from their dens and shoot them under new legislation enacted Wednesday, according to an animal rights group.
The winter den hunt left bear cubs orphaned,Â often resulting in their deaths, said the International Fund for Animal Welfare, which has been campaigning to endÂ the practice since 1995.
The new law reduces the hunting season for brown bears and Asiatic black bears and excludes the winter season, when the animals are hibernating in dens, the group said Wednesday. Under the new law, it is also illegal to hunt cubs less than a year old and females with cubs under one year.
"The 'rules of the hunt' legislation is a tremendous step forward for animal welfare in Russia and reflects the opinion of the Russian people that bears should be protected from this sort of hunting," said Maria Vorontsova, director ofÂ IFAW Russia.
To date, the group says it has successfully released more than 150 cubs from its rehabilitation center in Bubonitsy, Tver region.
Muhammad Ali made an impassioned plea as a "brother in Islam" to Iran's supreme leader for the release of two American hikers who have been held in the country since July 2009.
Josh Fattal and Shane Bauer were detainedÂ along with friend Sarah ShourdÂ on accusations of spying and trespassing after they allegedly strayed across an unmarked border into Iran while hiking in Iraq's Kurdistan region. Fattal and Bauer's espionage trial began in February without Shourd, who was released on bail in September 2010 because of a medical condition and immediately left the country. She has not responded to a court summons to return to stand trial,Â and authorities have said she will be tried in absentia.
In a brief letterÂ to Ayatollah â€©Sayyidâ€© Ali â€©Khamenei, Ali, a devout Muslim, asked the Supreme Leader to show the same compassion toÂ Fattal and Bauer that was bestowed upon Shourd.
"I â€©am â€©humbled â€©by â€©the â€©compassion â€©you â€©gave â€©to â€©their â€©young â€©female â€©friendâ€© Sarah â€©Shourd, â€©by â€©allowing â€©her â€©to â€©return â€©to â€©her â€©family. â€©â€©I â€©ask â€©the â€©sameâ€© mercy â€©and â€©compassion â€©be â€©given â€©to â€©them â€©as â€©well," he wrote.
Editor's note: CNN reporter Sandra Endo has relatives in Fukushima, Japan, one of the areas hit hardest by Friday's 9.0-magnitude earthquake and tsunami. Here, she writes of her relief on learning they're alive, and about her concerns about their proximity to a distressed nuclear power plant.
First it was the quake, now the radiation. The joy of finally hearing from my family in Fukushima after worrying for days is slowly becoming tepid.
My family in Los Angeles and I first heard from my 90-year-old grandmother, who lives in Fukushima City, on Tuesday night. We spent restless days and worrisome nights wondering how she was doing, wanting to hear her voice and find out her condition. We put all our faith in one text message that my cousin in Hiroshima received the night of the quake, saying that our family in Fukushima was accounted for, but what did that mean?
Besides my grandmother, my two aunts, two cousins and their four toddlers live 50 miles from the dangerously unstable Fukushima Daiichi nuclear power plant. They took in my cousin's in-laws, who live just 10 miles from the plant.
Fukushima City is my fatherâ€™s hometown. Itâ€™s a place where I spent summers playing in the streets with my cousins, going to the local ice cream shop and getting free firecrackers from neighbors during the summer festival season. It's where everyone knew whose kid you were and what shop your family ran for generations.
We were so happy to hear they all survived despite their grim stories of seeing neighbors' homes flattened, bodies being pulled from rubble and the scarcity of food and gas. Luckily, they recently installed a new water pump, which withstood the massive quake. My family was providing water for the community, because many were without.
They told us they were sealing off their house as best they could to prevent radiation from seeping in. That meant patching up one wall of the house that collapsed during the quake. The broken dishes, glass and strewn furniture didnâ€™t matter, because all that could be replaced orÂ cleaned. Now the worry is the radiation.
On Thursday, the U.S. Embassy in Japan issued an evacuation noticeÂ for Americans who live 50 miles from the power plant; officials found traces of radiation in the tap water in Fukushima. My family lives within that zone with no wayÂ and no place to move.
The fear is even taking hold in Tokyo, hundreds of miles south of Fukushima, where people are trying to get out of the country.
With the gas shortage, only emergency crews are fueling up, so driving is not an option for my family. My grandma says evacuation centers are already filled.
With the patience and spirit only a 90-year-old could have, she says she will wait, stay in her hometown and make the best of it. She says sheâ€™ll celebrate life, not worry about the possible danger that lurks. She tells me sheâ€™s glad Iâ€™m not there and CNN crews have left the area; she says itâ€™s safer that way. But I say: Grandma, thereâ€™s no place Iâ€™d rather be.
Four journalists for The New York Times are missing in Libya, the newspaper said Wednesday on its website.
The Times said the missing journalists are Anthony Shadid, the paper's Beirut bureau chief and two-time Pulitzer Prize winner; Stephen Farrell, a reporter and videographer who was kidnapped by the Taliban in 2009 and rescued by British commandos; and two photographers, Tyler Hicks and Lynsey Addario.
"We have talked with officials of the Libyan government in Tripoli, and they tell us they are attempting to ascertain the whereabouts of our journalists," executive editor Bill Keller said. "We are grateful to the Libyan government for their assurance that if our journalists were captured they would be released promptly and unharmed."
Under cold and overcast skies, a ferry pulled into the harbor in Kesennuma, Japan. The captain shouted to people on the shore to grab a rope and help tie down his boat.
With the dock underwater, crushed by Friday's tsunami, this is the only way the ferry has been able to return to service. Dozens of people, wearing masks and carrying bags, load onto the boat for the 20-minute trip to Oshima island. For many, this is the first time to get to their friends and loved ones who have been stuck on Oshima since the earthquake. American Paul Fales was one of the first passengers off the ferry from Oshima. A slight man of 25, he looked pale, cold and anxious as he made his way off.
He'd ridden out the massive earthquake in the elementary school where he was an assistant English teacher. High ground protected the students when the tsunami rushed in, and he was back in Kesennuma to see how his apartment had survived. In spite of the debris around him, he was confident.
"I think it will be fine, really," he said. But that short walk would prove challenging â€” the streets impassable and filled with water, debris and mud. A roof fell into the center of another street, and we couldn't get around it. We turned back again.
A voice called, "Paul!" A woman in a flannel jacket, with a hat jammed over her ears, ran across the street and hugged him. "You're OK!" she said. She started crying as she hugged him, and started to list their friends that she knew had survived. Rachel Shook is also an assistant teacher.
Photographer films grenade attack– CNN iReporter Gyula SopronyiÂ shot this disturbing video of a rocket-propelled grenade attack against rebel forces in Libya. She says the grenade was fired by pro-GadhafiÂ forces in Ras Lanuf, where the country's largest crude-processing plant is.[cnn-videoÂ url="http://www.cnn.com/video/#/video/world/2011/03/15/ireport.libya.rocket.launch.cnn"%5D
Dutch researchers found the wreck of a World War I German submarine in 2009 but kept the discovery secret until this week, Radio Netherlands Worldwide reported.
The crew of the research ship HNLMS Snellius hoped they'd found a Dutch submarine that disappeared in 1940, but the vessel turned out to be much older. A brass plate indicated the sub was the German U-106, which sank during World War I, the radio report said.
The announcement of the discovery was delayed while German officials confirmed the sub's identity and sought out relatives of crew members, according to the radio report.
A Dutch navy spokesman told Radio Netherlands the U-boat would not be raised but would be designated a war memorial.
Federal officials have seized Georgia's supply of a drug used in executions while they investigate whether it was imported legally, the Atlanta Journal-Constitution reported Wednesday.
Spokespeople for the Drug Enforcement Administration and the Georgia Department of Corrections told the newspaper the state's supply of thiopental had been seized.
Thiopental is available only from international sources, since the drug's sole U.S. manufacturer, Hospira, stopped making the sedative in 2009. But the countries where the drug is made do not allow its export if it is going to be used for capital punishment, the Journal-Constitution reported.FULL STORY
Watch CNN.com Live for continuing coverage of the crisis in Japan.
Today's programming highlights...
Ongoing coverage - Japan earthquake/tsunami aftermath
9:30 am ET - Energy secretary talks Japan, budget - Energy Secretary Steven Chu testifies before a Congressional committee on budget priorities.Â He is also expected to take questions on the Japan crisis and possible U.S. ramifications.