[Posted at 2:51 p.m.] A woman has died as a result of Wednesday's building collapse in Philadelphia, two sources close to the investigation told CNN's Don Lemon.
No death was mentioned at the news conference that wrapped up near the site minutes ago.
[Posted at 2:43 p.m.] Fourteen people have been rescued from the site, 13 of whom have been hospitalized, officials told reporters moments ago.
Mayor Michael Nutter said that a search-and-rescue operation continues.
"Keep in mind we did not know, and we do not know, how many people were actually in the thrift store this morning when the wall collapsed this morning," and that's why the search continues, Nutter said.
[Posted at 2:16 p.m.] A Salvation Army official had this to say about the collapse that damaged the Salvation Army store:
"At this time, we are gathering information about the details of the building collapse at 22nd and Market Street in Philadelphia today. Our No. 1 concern is for the safety of our customers and the employees who were involved," Donald Lance, divisional Leader of the Salvation Army's Eastern Pennsylvania and Delaware Division, told CNN's Natalie Apsell.
"We are coordinating with the police and fire Department, the Office of Emergency Management and local authorities," Lance continued. "Also, we have sent our own disaster response team to the site to serve survivors and first responders. We ask for the public to pray for those involved."
[Posted at 2:13 p.m.] Mike Adam, who lives across the street from the site, says he took this picture from his apartment:
Adam told CNN's Brooke Baldwin that he and his fiancee were in their apartment when they heard sirens. He looked out a window and saw people running. Looking out a different window, he saw smoke and rubble.
"A block over, there's a fire department, so they were on the scene almost immediately," Adam said.
[Posted at 2:01 p.m.] While firefighters have been digging through the rubble, people from a nearby market have "graciously supplied (them) and officers with fresh apples and bananas," CNN iReporter Josh Rozell says.
[Posted at 1:30 p.m.] Philadelphia firefighters have just made another rescue, the city's mayor said.
A person who was buried in the rubble "for about two hours" was rescued by city fire personnel, Philadelphia Mayor Michael Nutter told CNN's Don Lemon minutes ago.
That person has been taken to a hospital with minor injuries, and it bring to 13 the number of people taken to hospitals, Nutter said.
Nutter said he didn't know how many other people might be trapped, noting that officials don't yet know how many people were inside the store.
[Posted at 1:21 p.m.] To give you an idea of where this happened: The site is in a heavily traveled area of downtown Philadelphia near the Mutter Museum, a popular tourist destination that houses medical oddities.
The museum was closed Wednesday due to the collapse, it said on Twitter.
[Posted at 1:12 p.m.] Witness Jordan McLaughlin told CNN affiliate KYW that firefighters arrived at the site just minutes after the collapse.
[Posted at 1:05 p.m.] Going back to what witness Jordan McLaughlin told CNN affiliate KYW - This is how he described what officials say was the under-demolition four-story building falling onto the adjacent Salvation Army store:
"(The building) collapsed the wrong way, and it landed on a thrift shop" that had people inside, he said. "It was scary. What happened next was a I dropped my stuff and I tried to help people out."
He said he helped two people out of the rubble, and others assisted a few other people in the first 10 minutes or so. After that, first responders asked him and other non-emergency personnel to leave the area.
"When the building collapsed ... there (were) people standing on the corner that (were) right next to the thrift shop. The building ... had really big aftershock on the ground. You felt it shake. There (were) people that actually fell over. People started screaming. They ran across the street.
"There (were) people inside the building. You heard them scream. Then we (Jordan and others nearby) went over to the building. We said, 'Can you hear us, can you hear us? Say something.' And we tried to find the people."
[Posted at 12:52 p.m.] “This is an active search and rescue. It’s ... delicate and dangerous.” Philadelphia Mayor Michael Nutter told reporters.
The Salvation Army store had “workers and customers” at the time of the collapse, so it is difficult to know exactly how many others are trapped in the rubble, he said.
[Posted at 12:40 p.m.] A four-story building that was being demolished apparently fell onto a smaller building with a Salvation Army store in central Philadelphia at about 10:45 a.m. Wednesday, injuring and trapping a number of people, Philadelphia Fire Commissioner Lloyd Ayers said moments ago.
Two people are still believed to be trapped beneath the rubble, and emergency personnel are trying to extricate them, Ayers said. Twelve people have been taken to hospitals, he said.
The 12 injured people either have minor injuries or are in stable condition, he said.
[Posted at 12:31 p.m.] Witness Ari Barkin said the set-for-demolition building that fell onto the thrift shop was about three stories tall. The taller building used to house an adult bookstore, he said.
Witness Jordan McLaughlin told CNN affiliate KYW that the collapse made the ground shake, and some near him fell over.
[Posted at 12:15 p.m.] As many as 10 people are believed to be trapped following what officials say was an accident at a demolition site in Philadelphia Wednesday morning, city Fire Commissioner Lloyd Ayers said, according to CNN affiliate WPVI.
A witness, Ari Barkin, told CNN that a part of an unoccupied building set for demolition fell onto a one-story Salvation Army building. Debris also hit three cars and a sidewalk, he said.
Another witness, Jordan McLaughlin, told CNN affiliate KYW that a number of people were in the Salvation Army building, and that he helped pull two people from the rubble.
The Occupational Safety and Health Administration has been told it was an accident at a demolition site, and it has investigators on the way, representative Leni Fortson said.
The collapse happened in the Center City area, at 22nd and Market streets, WPVI said.