By Dave Warner
PHILADELPHIA (Reuters) - A building collapsed in downtown Philadelphia on Wednesday, killing a 35-year-old woman and injuring 13 other people under in mountains of crushed concrete and splintered wood, officials said.
Search and rescue efforts continued late in the day for more survivors of the collapse, which occurred around 10:45 a.m. when a four-story building under demolition fell onto a neighboring two-story Salvation Army Thrift Store, said Philadelphia Fire Commissioner Lloyd Ayers. Rescue workers were expected to remain on the scene for 24 hours.
Philadelphia Mayor Michael Nutter confirmed the death of the woman, but declined to offer additional details. Survivors pulled from the rubble suffered minor injuries and were taken to area hospitals, where they were in stable condition, he said.
One witness, Dan Gillis, 31, of Cinnaminson, New Jersey, a construction worker on a job across the street, said he saw a crane remove a supporting beam from the front of the building, and then the wall next to the thrift store started swaying.
Another witness, Jeffrey Fehnel, 48, of Philadelphia, said about the same time a backhoe hit the rear side of the building.
"The building came down. It was like a big blast," Fehnel told Reuters.
Authorities said the cause of the collapse, which occurred at 22nd and Market streets in the heart of Philadelphia's Center City, was still under investigation.
"We have two dogs that have come out to work the pile to locate others so we know exactly where to dig," Ayers said. "We're moving a little bit at the time."
Nutter told reporters at a news conference at the site that it was unclear how many people had been in the thrift store when the collapse occurred.
A witness told Reuters the building collapse shook the ground and knocked a man off his feet on the sidewalk outside the thrift store.
"It was ground-shaking. The shaking of the ground made the man fall down," said Jordan McLaughlin, 18, of Philadelphia.
Police urged the public to stay away from the area while rescuers dug through the rubble.
Authorities said the building that was being demolished had housed an X-rated book and video store. They said it was owned by Richard Basciano, a well-known owner of adult entertainment properties including Philadelphia's last X-rated movie house, which closed in 2012, and a New York Times Square pornography emporium known as Show World, which closed in 2004.
Basciano did not immediately respond to a call seeking comment.
(Reporting by Barbara Goldberg; Editing by Maureen Bavdek, John Wallace, David Gregorio and Steve Orlofsky)