The accident occurred at 10:45am local time in a pair of four-story buildings, reportedly slated for demolition, on the corner of 22nd and Market Streets.
A Salvation Army thrift store on the corner was also affected by the collapse as debris came through its roof.
A dozen people have been rescued from the rubble. They all sustained minor injuries and were transferred to the city’s Hahnemann, Jefferson and the University of Pennsylvania hospitals.
Philadelphia Fire Commissioner, Lloyd Ayers, told the press that two more people remained in the rubble, with the rescuers working to extract them.
Shortly before 1pm, a 66-year-old female was pulled from the debris alive.
At about 2pm, the emergency workers removed the body of the deceased victim from the Thrift Store, whose identity wasn’t revealed.
Parts of Market Street and 22nd Street near the scene of the collapse have been closed to traffic.