Building collapse in Philadelphia

Emergency personnel and others rescue a man from the rubble of a building collapse on the edge of downtown Philadelphia on Wednesday.  (Jordan McLaughlin / Associated Press)

Firefighters view the aftermath of a building collapse Thursday in Philadelphia. On Wednesday, the building under demolition collapsed onto a neighboring thrift store, killing six people and injuring 14, including one who was pulled from the debris nearly 13 hours later.  (Matt Rourke / Associated Press)

A firefighter sprays the debris a day after a building collapsed in Philadelphia.  (Matt Rourke / Associated Press)

A sign from the Salvation Army thrift store demolished in building collapse is removed from debris Thursday in Philadelphia.  (Matt Rourke / Associated Press)

The scene of a building collapse on the edge of downtown Philadelphia on Wednesday.  (Russell Krause / Associated Press)

Rescue personnel remove debris from the area of a collapsed building in downtown Philadelphia.  (Jacqueline Larma / Associated Press)

The four-story building being demolished on Wednesday, hours before it collapsed in Philadelphia.  (Luis Cornejo / Associated Press)

Emergency personnel respond to a building collapse in downtown Philadelphia, where the city fire commissioner says as many as 10 people are believed trapped in the rubble.  (Jacqueline Larma / Associated Press)

Rescue personnel evacuate an injured person from the scene of a building collapse in downtown Philadelphia.  (Jacqueline Larma / Associated Press)

Police keep onlookers behind yellow tape near a building collapse in downtown Philadelphia.  (Jonathan Hudson / Associated Press)