Department of Licenses and Inspections Commissioner Carlton Williams should be fired, City Controller Alan Butkovitz said, because the department has not made enough progress on promised reforms. 

"If you can't get immanently dangerous buildings knocked down, when you've had two years and nine months, then what are you doing that warrants your stewardship?" Butkovitz asked at a press conference Wednesday. 

A new report by Butkovitz's office says that the department allowed trainees to perform inspections —despite lacking necessary certifications, and the department has failed to knock down dangerous abandoned buildings despite repeated warnings to do so.

RELATED: L&I Commissioner disputes audit of demolition inspections

But Mayor Michael Nutter has come out strongly in defense of Williams, saying he's the best the department has had in years.

"With new regulations and ordinances, L&I is overseeing safety issues at construction and demolition sites like no other L&I in the past," the mayor's office said in a statment.

The release marks the third time Butkovitz's office has audited L&I since 2013, when an accident at a Center City demolition site killed six people after the building being demolished toppled onto a neighboring Salvation Army store. 

After the collapse, Mayor Michael Nutter promised sweeping reforms at the department.

Butkovitz said illegal demolition, construction without permits, and building collapses continue. And, he said, the department has remained uncooperative, forcing him to issue subpoenas to get information from the city agency.

A new computer system, announced in January 2014, has yet to be implemented, the controller's office said. 

Employees have widespread ability to abuse overtime, Butkovitz said. Only one supervisor needs to approve it, and rarely is documentation adequate to show why an employee needed to work overtime. 

RELATED: City Controller subpoenas L&I for demolition reports

In Fiscal Year 2015, the department's overtime budget stood 235 percent above budget. The department budgeted $485,000 for salaries — but spent $1.6 million because of overtime. 

The Nutter Administration countered with his own figures:

"The Department with support from the Mayor and Council has dramatically increased the number of (Immanently Dangerous) building demolitions each year, reducing the stock from an average of about 600 to about 270. The Department has increased clean and seals from 1,400 per year to 2,100 and we’ve inspected 13,000 vacant buildings, cited them where necessary and  36 percent of them have come into compliance without going to court," the administraton said. 

Even with the mayor's support, Williams' days at L&I could be numbered. Jim Kenney, the Democratic nominee for mayor, has said that he would replace Williams.