A SLEW OF Harrisburg heavyweights came to Penn's Landing yesterday and joined the long list of officials who are asking whether regulators can do more to prevent another tragedy like the Center City building collapse that killed six people last month.

The group, which included six House committee chairs, heard testimony on a bill from state Rep. Bill Keller that would, in part, add requirements for demolition-permit applicants and raise fees to fund additional training for city inspectors.

"This is public safety," Keller, a South Philly Democrat, said of the need to increase regulations. "You can't argue with what happened a month ago."

Keller's bill would raise construction permits by 15 percent and put the money in a new fund for construction-code training and enforcement. It would also require state regulators to annually review the qualifications of Philly officials who implement the code.

The bill would make permit applicants submit safety plans, have liability insurance and notify neighbors near upcoming demolitions, among other requirements.

Mayor Nutter announced a series of policy changes following the collapse, including similar requirements for permit applicants. City Council is also looking into the incident and has convened an investigatory committee.

Yesterday's event, a joint hearing of the House's Urban Affairs and Labor and Industry committees at the Independence Seaport Museum, featured testimony from labor-union leaders and industry experts. Keller is the top Democrat on the Labor and Industry Committee.

City Licenses & Inspections Commissioner Carlton Williams did not attend the hearing, but submitted written testimony, in which he said L&I supports the "general intent" of Keller's bill but did not address any specific provisions.

He also detailed the city's demolition regulations and steps L&I has taken since the June 5 collapse.

"Let me be clear - this tragedy was not a regulatory failure, nor an enforcement failure on the part of L&I," Williams wrote. "This tragedy happened even though L&I made all of the site inspections required by the Code. However, this tragedy reminded us that we must continue to go above and beyond what is required."

Nutter spokesman Mark McDonald said Williams had a prior commitment.

The collapse, at 22nd and Market streets, occurred when an unsupported wall from a demolition site fell onto a Salvation Army store next door, crushing those inside. Since the deadly incident, many have questioned whether the city's demolition regulations are too lax.

The property is owned by Richard Basciano, whom the New York Times once called the "porn king" of Times Square, and the project was handled by a contractor with a questionable past. The excavator operator, Sean Benschop, has been charged with involuntary manslaughter.