Bennett Levin, a professional engineer who ran the Department of Licenses and Inspections in the Rendell administration, testified Thursday that the agency's performance had deteriorated markedly since the mid-1990s, contributing to a series of fatal accidents long before the Center City building collapse in June that killed six people.

"The Market Street collapse is just the latest catastrophe in a tragic string of fatal events that can be traced back to the [One Meridian] fire, with three dead firefighters," in 1991, Levin told a City Council committee investigating the city's demolition practices.

He cited the 1997 death of Common Pleas Court Judge Berel Caesar, hit by debris from a dilapidated parking garage on South Broad Street; the collapse of Pier 34, which claimed the lives of three young women in 2000; and the deaths of two firefighters last year in a vacant Kensington mill.

All were events that led to "what happened on Market Street," said Levin, who was L&I commissioner from 1992 through 1995.

Levin compared L&I's duties to those of the Police and Fire Departments, suggesting that it had subordinated its public-safety responsibilities to "political expediency and economic development."

"No right-thinking person would tolerate managing either the Police Department or the Fire Department in the manner in which L&I has been managed," Levin said in stinging remarks read from an 11-page statement.

Mayor Nutter issued a statement suggesting that Levin was out of touch with the department's current operations.

"The former commissioner has a right to his opinion as a private citizen, but many things have changed in the Department of Licenses and Inspections in the almost two decades since he was in city government," the mayor's statement said.

"I cannot imagine that he meant to slander the reputations of the many fine people who work at L&I. I cannot comment on what happened prior to this administration, but the department has made significant improvements in recent years while maintaining its mission of public safety."

Nutter said L&I "now approaches that mission with a more qualified staff, improved technology, and streamlined processes. . . . There will always be work to do as we continue to improve our processes throughout city government, but I am proud of what has been accomplished."

Levin praised several of L&I's current executives by name, including the deputy commissioner, Michael Fink, described by Levin as a top-notch expert on building safety and demolitions.

But he said "the rigorous skills required of inspectors" had been watered down by cross-training programs designed to expand the types of inspections that employees could perform.

"Book-learning and good testing abilities do not make for competent inspectors," Levin said. "There is a need for real and hands-on building-trade experience if you desire excellence from the inspection staff."

"It used to be, plumbing inspectors were actually master plumbers," Levin said in an interview after the hearing. "Now, you can take a test, and they say you're certified, but that doesn't go to your practical experience. . . . Out in the field, these people [inadequately trained inspectors] become insecure and defensive."

Levin, now 73 and living in Bucks County, said he was aware of current problems at the agency because he has maintained relationships with current and recently retired L&I employees.

The Council hearing was the fourth conducted by a special committee created after the June 5 building collapse.

Six people were killed and 14 injured when an unsupported wall at a demolition site fell on a neighboring Salvation Army thrift store full of employees and customers.

A heavy-equipment operator, who authorities say had marijuana in his system at the time of the collapse, has been charged with manslaughter.

District Attorney Seth Williams has convened a grand jury to conduct a criminal investigation.

Generally, the Council committee has avoided specific questions about the June collapse. But Council members veered from that course Thursday with several witnesses.

The most dramatic exchange was between Councilwoman Cindy Bass and former L&I Commissioner Fran Burns, who stepped down in June 2012.

Bass pressed Burns to describe her thoughts when she heard about the building collapse.

"What was your reaction when this happened on Market Street?" Bass asked. "Did you feel you were shocked and surprised as commissioner, with all the controls you had left in place? Were you not surprised? Maybe you thought things were a little bit lax, and this could happen?"

"I don't have a response to that," Burns replied. "I don't know that that question really matters in the context. . . ."

"I think it does matter," Bass said, "because we can't look forward unless we look backward, look back at what we've done, what processes we had in place, what precautions. . . . How did we get here? . . . I think that's why you're here."

"You're asking about something I don't feel comfortable speculating on," Burns said.

"I wasn't asking for your speculation, just your thoughts," Bass replied. "But never mind. . . ."

Robert Mongeluzzi, an attorney for several victims of the collapse, was invited to testify based on his 25 years of experience investigating construction accidents.

Generally, Mongeluzzi avoided mentioning the Market Street collapse, but after he referred to a federal requirement that an engineering survey be completed in advance of any demolitions, Councilman Bobby Henon pressed to find out whether there had been such a survey for the building at 2138 Market St.

"I have been told by multiple sources," Mongeluzzi said, "that there was no engineering survey as required" by the Occupational Safety and Health Administration.