A fire at the One Commerce Square high-rise office building in Center City on Sunday morning was contained to the rooftop cooling tower, according to the Philadelphia Fire Department.

Firefighters were dispatched to the 41-story building at 20th & Market Streets about 11:15 a.m. after getting multiple calls about smoking coming from the roof, spokesperson Kathy Matheson said. Firefighters had the flames under control at 11:37 a.m. with no spread to the building’s interior, Matheson said.

Shortly before 11:30 a.m., social media posts showed flames and thick black smoke rising from the roof of the building, one of a pair of twin office towers distinguishable by diamond-shaped cutouts at their tops.

More than a half-dozen fire trucks responded to the scene, the high-rise largely empty given the weekend and the continuing work-from-home practices by many companies since March 2020 due to the coronavirus pandemic.

Staff writer Ryan W. Briggs contributed to this article.