The inspector, Ronald Wagenhoffer, was the last city official to check on construction at the doomed building and found no violations during his inspection on May 14.
On June 5, while the building was being demolished, it toppled onto a smaller two-story building that housed a Salvation Army thrift store. Workers and shoppers in the thrift store were crushed in the rubble. Fourteen were rescued and treated for injuries while six people died.
Officials said that Wagenhoffer died in his truck Wednesday night of a gunshot wound to the chest, which was apparently self-inflicted. He worked for the city for 16 years.
"We're a city in deep and profound mourning. With the building collapse a week ago we have now lost seven lives with this tragedy," Deputy Mayor Everett Gillison said today. "We're still burying people from last week, now we have to bury someone from today."
The city faced criticism for not inspecting the demolition site after May 14, and the tragedy raised questions about inspection policies. Gillison said that Wagenhoffer did nothing wrong leading up the collapse, and defended the city's inspection department.
"For us, you have to understand that there are now five investigations (into the collapse), but right here and right now, this man did nothing wrong," Gillison said. "The department did what it was supposed to do under the code as it existed at the time. We are proud of this department and its employees, period."
According to city officials, Wagenhoffer continued going to work each day after the building collapse and did not express difficulties to anyone. The commissioner of the buildings inspection department had reached out to Wagenhoffer to check in with him, but had not had the chance to speak with him yet.
"He came into work everyday, was continuing doing inspections, people were reaching out to him," Gillison said. "He did his job and did it the way he was supposed to be doing it."
Gillison emphasized that there had already been an arrest of a construction crew member who was allegedly operating a crane under the influence of marijuana and painkillers when the building's wall fell down.
He said that Wagenhoffer was not being targeted by the investigation.
"This is a criminal investigation, which means criminal behavior is alleged and it was not on Mr. Wagenhoffer," Gillison said.
The Philadelphia District Attorney is convening a investigative grand jury to look into what other factors led to the collapse, according to ABC News affiliate WPVI.