Surveillance video from a city bus captures the moment a building under demolition collapsed in Philadelphia's Center City last month.

Two employees and four customers were killed during the June 5 collapse, when a building under demolition crumbled on top of the Salvation Army thrift store at 22nd and Market Street in Center City.

In the upper right hand corner of the SEPTA bus video, you can see the collapse followed by plumes of smoke pouring into the street. Several people run away but then stop in the street to look at what happened.

Thirteen people were rescued from the rubble of the collapse.

"I think that this video supported what my thoughts have been for the last month. And that is, that this was a failure in planning, not a failure in execution," says Robert Mongeluzzi, a lawyer representing several of the victims.

As we get this first look at video of the collapse, city officials are in the middle of a third public hearing into the deadly collapse. City Council hoped to question Licenses & Inspections and officials with the Philadelphia Fire Department, but they've declined to testify with the investigation still ongoing.

Kary R. Roberts, also known as Sean Benschop, is the only person charged in connection with the collapse. Investigators with the District Attorney's Office says Roberts was impaired by marijuana and painkillers while operating heavy equipment.

Roberts is charged with six counts of involuntary manslaughter and 13 counts of reckless endangerment. A grand jury will decide if anyone else should face charges.

A Philadelphia Licenses & Inspections worker, responsible for inspecting the building that collapsed, committed suicide one week after the deadly collapse.

In a final recorded message, 52-year-old Ronald Wagenhoffer says he couldn't sleep. He admitted he never truly inspected an adjacent work site after a citizen complained about safety concerns, although he reported there were no violations found.

"When I saw it was too late. I should have parked my truck and went over there but I didn't. I'm sorry," Wagenhoffer said in the message.