The collapse occurred shortly after 3:30 p.m. at the 102-year-old Levoy Theater on 128 North High Street.
Buildings adjacent to the theater were also damaged.
The collapse triggered a gas leak.
Several blocks surrounding the theater were evacuated as emergency personnel dealt with the collapse and gas leak.
The Levoy Theater was in the process of an $8.5 million restoration.
Parts of the theater were recently demolished, and reconstruction was set to begin soon. Crews worked last week breaking loose an interior wall.
Workers on site were able to evacuate the building before the roof caved in.
One responding firefighter was injured. The extent of his injuries is unclear, though they are said to be non-life-threatening.
Plans called for the renovated theater to have a new stage, orchestra pit, concession booth, 700 seats and electrical and sound systems.
The Associated Press contributed to this report.