PHILADELPHIA (AP) -- As a bulldozer began to clear away the debris of a collapsed building that killed six people, city officials said a search for the dead and injured was nearly complete Thursday and an investigation had already begun to determine how a relatively commonplace demolition job could have gone so wrong.
Fire Commissioner Lloyd Ayers said crews still needed to search about 20 percent of the site of the collapse, including the back of a thrift store onto which the vacant four-story building collapsed while being demolished. The search effort was expected to last through the afternoon.
Firefighters were hosing down piles of bricks as heavy machinery scooped up massive heaps of debris and filled a large receptacle to be trucked away. Inside what was left of the Salvation Army thrift store, an undisturbed rack of clothing remained standing in a rear corner.
Rescue efforts were buoyed early Thursday when a 61-year-old woman was pulled from the rubble alive and conscious 13 hours after the collapse. That woman, Myra Plekam, was hospitalized in critical condition and has floated in and out of consciousness. At least 13 others were hurt, many with minor injuries.
"That's why we stay the course," Ayers said. "This person being pulled out alive is what this rescue operation is all about."
Workers combed through bricks and rubble using buckets and their bare hands well into the night.
It was unclear what role the demolition work might have played in the collapse, but the accident raised questions about how closely the highly visible spot on Market Street, one of Philadelphia's signature boulevards, was being monitored, particularly amid word of the demolition contractor's many legal and financial troubles. Officials from the U.S. Department of Labor and Occupational Safety and Health Administration were at the scene.
"Buildings get demolished all the time in the city of Philadelphia with active buildings right next to them ... they're done safely in this city all the time," Mayor Michael Nutter said at a news conference late Thursday morning. "Something obviously went wrong here yesterday, and possibly in the days leading up to it. That's what the investigation is for."
Officials said every demolition project gets two inspections — one before work begins and a second when most of the building is down. The building that collapsed was one of three being taken down at the edge of downtown. Officials said they received a complaint in early May when the neighboring building was being demolished. An inspector visited the site on May 14 and found no violations, officials said. They said the building that collapsed was still fully intact on the date of that inspection.
For weeks, people working nearby had watched with growing concern as a crew took down the vacant four-story building next to a Salvation Army thrift store.
A roofer atop another building didn't think the operation looked safe. A pair of window washers across the street spotted an unbraced, 30-foot section of wall and predicted among themselves the whole building would simply fall down.
On Wednesday, that's what happened. The unstable shell of a building collapsed into a massive heap of bricks and splintered wood, taking part of the thrift store with it.
Witnesses said they heard a loud rumbling sound immediately before the collapse.
Officials said the demolition contractor was Griffin Campbell Construction in Philadelphia. A woman who answered the door Thursday afternoon at Campbell's home in North Philadelphia said he was not there but added he was "devastated" by what happened.
"He's mourning the loss of those people just like everyone else," said Dominique Lee, who identified herself as Campbell's daughter.
She said her father has a lawyer but declined to provide the attorney's name.
Records show that Campbell was charged in 2005 with dealing crack cocaine near a playground. The charges were dismissed after prosecutors misplaced evidence.
He pleaded guilty in an insurance fraud case in 2009, and was acquitted of aggravated assault and related offenses in 2007.
Campbell has also filed for bankruptcy protection twice since 2010. The first bankruptcy was dismissed because he didn't follow through on a repayment plan approved by the court. A second bankruptcy petition was filed in March.
There were no existing violations on the collapsed building, and Campbell had proper permits for the work being done, according to Carlton Williams, of the city's Department of Licenses and Inspections.
The city issued a demolition permit for the four-story structure on Feb. 1. Records show the property owner as STB Investments Corp., a company linked to prominent businessman and developer Richard Basciano, who has been best known as the owner of porn theaters in New York City and Philadelphia.
Messages left at the company's New York offices were not immediately returned.
Rubinkam reported from northeastern Pennsylvania. Associated Press writers Ron Todt and Maryclaire Dale also contributed to this story.