Amid growing pressure and swirling controversy, New York City's embattled buildings commissioner resigned Tuesday after six turbulent years in office.

Patricia Lancaster, who was the first woman to lead the city's Dept. of Buildings, handed in her resignation just a day after Mayor Michael Bloomberg criticized the agency in the wake of several high-profile on-site accidents and a spike in construction-related deaths.

"After six years in public service, I made this decision because I felt it was time to return to the private sector," Lancaster said in a statement released Tuesday morning.

Lancaster, an architect, was hired in 2002 to help bring the city's often-overlooked department up to date. And while New York has enjoyed an unprecedented construction boom over the last few years, several recent fatal accidents on high-rise sites had called into question her ability to effectively run the agency. So far in 2008 there have been 13 construction-related deaths. In all of 2007 there were 12. Most recently, a a crane collapse on Manhattan's Upper East Side killed seven construction workers and destroyed portions of several nearby buildings.