The Pittsburgh casino reached a milestone today when iron workers put into place the last piece of structural steel for the building's skeleton.

The "topping off" ceremony keeps the casino, being built on the North Shore just west of the Carnegie Science Center, on pace for an August 2009 opening. Crews hope to have most of the building enclosed from the elements in December, enabling interior work to begin, said Ed Fasulo, the casino's general manager.

Mr. Fasulo said the milestone was particularly gratifying given the financial troubles the casino faced last summer, ones that for a time imperiled its future.

"This is a big event for us. We're excited to get it done," he said. "This easily could have been sitting here rusting away for five years."

The last beam was signed by workers at the site before being put into place. It was adorned with an American flag, a Christmas tree, and a broom, signifying "a clean sweep and no injuries on the job."