Gathered outside a hulking, vacant North Philadelphia commercial building, city officials Wednesday announced a joint initiative between the Department of Licenses and Inspections and the Fire Department to inspect derelict properties.

The idea is to evaluate dangerous, empty structures larger than 15,000 square feet - so-called mantraps - for the safety of firefighters and the public. Many such buildings, like the one at 3617 N. Eighth St., will be demolished.

But the media event, attended by Mayor Nutter, L&I Commissioner Carlton Williams, Fire Commissioner Derrick Sawyer, and others, also appeared to serve as a forum to bolster Williams as he and his beleaguered department weather a barrage of criticism.

"Thank you for your leadership of one of the most important safety departments in Philadelphia," Nutter said to Williams in front of a crowd that included reporters, about two dozen L&I employees, and two members of City Council.

Soon after, Nick DeJesse, director of the Philadelphia office of the federal Occupational Safety and Health Administration, praised L&I for identifying dangerous situations for workers throughout the city, such as unsafe excavations. DeJesse said that with the agency's help, OSHA was able to remove 250 workers from potentially risky situations between October 2013 and March of this year.

"That's good work," DeJesse said.

The public show of support comes as the agency is enduring revelations of various problems on Williams' watch, including: last spring's demolition of a half-block of Fairmount without permits; the inspections of 181 unsafe properties by nine uncertified inspectors in February; the construction of a building housing Temple University students built between 2013 and 2014 without permits or inspections; and the failure to inspect dangerous and unsafe buildings throughout the city in time frames stipulated by law.

While no one at the media event mentioned these difficulties, City Controller Alan Butkovitz did, later in the day.

"I guess it makes sense to call the Fire Department if you're trying to put out a fire at L&I," he said. "This event was an exercise in public relations and deflection."

The Nutter administration made a series of promises after the fatal Center City building collapse in June 2013 to improve demolition and construction immediately, Butkovitz said. But, he added, "we've found repeatedly it's not been true."

L&I inspectors who did not want to be identified for fear of retribution called the event "a dog and pony show" meant to say to the media that L&I was in firm control of the building stock in a city with more than 25,000 vacant properties.

Inspectors wondered why the Eighth Street building wasn't demolished years ago.

"Why are they doing this now?" one asked. "They seem to be on a campaign to show how well they're doing."

A Nutter administration spokesman said the demolition was recently ordered by a court. L&I is working "assiduously" to remove dangerous buildings, the spokesman added.

After the speeches Wednesday, those at the site were invited by the demolition company to watch the first bricks of the aged building fall.

But like many other things related to L&I lately, not everything went smoothly. Sources said the demolition had to be halted after OSHA determined that power lines were too close to the building and threatened worker safety.

The city spokesman denied that, saying the demolition had started in a location "where Peco did not need to de-energize the lines."

But a spokeswoman for Peco said Wednesday night that L&I contacted the utility on Wednesday afternoon to de-energize the power lines closest to the site. She said Peco was working with the city to determine when the power could be cut.