DO NOT PUB: Crews end search at Philadelphia building collapse site

PHILADELPHIA (REUTERS) - Rescue workers on Thursday ended their search for survivors of a downtown Philadelphia building collapse, a day after a structure under demolition collapsed on shoppers and staff at a neighboring thrift store, killing six people and injuring 14 others.

The effort was called off at 4.30pm EDT (4.30am Singapore time), following an around-the-clock search for life amid a mountain of crumbled concrete and splintered wood, said Fire Commissioner Lloyd Ayers.

Late on Wednesday, 12 hours after the morning collapse, a 61-year-old woman was pulled from the debris and rushed to the hospital in critical condition. Earlier, six people were found dead and 13 others were rescued with minor injuries.

"All of the despair with the people who were deceased, that person being pulled out alive is what every rescue is all about," Mr Ayers said on Thursday.

Investigators are still trying to determine what caused the collapse of the four-story building, which collapsed onto a neighboring Salvation Army Thrift Store, burying shoppers in the debris.

On the scene investigating were Philadelphia police, Philadelphia Licenses and Inspection and the Occupational Safety and Health Administration.

Authorities have declined to identify the dead other than to say that they included one man and five women who were inside the store when the building next door came down.

Most of the injured were also thought to have been inside the store or on the sidewalk in front of it at the time. Aside from the last woman rescued, most were said to be in stable condition or have already been released from the hospital.

Witnesses to the sudden collapse, which occurred at 22nd and Market streets in the heart of Philadelphia's busy Center City district, said it shook the ground and knocked people on the nearby sidewalk off their feet.

One witness, Mr Dan Gillis, 31, a construction worker from New Jersey who was 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 began to sway.

Mr Jeffrey Fehnel, 48, of Philadelphia, said a backhoe hit the rear side of the building at about the same time. "The building came down. It was like a big blast," he told Reuters.

Authorities said the building that was being demolished had housed an X-rated book and video store.