An electrical fire broke out at the old Main Chicago Post Office building Sunday evening.
Firefighters were alerted to the fire on the roof of the 14-story building located at 433 W. Van Buren about 7 p.m., said Fire Media Affairs Director Larry Langford.
Extra crews were called in after firefighters discovered that the building's water pipes were not working properly, Langford said. Water pumped into the pipes was not traveling to the roof, an indication that there might be a leak, Langford said.
As a precaution, the Chicago Fire Department initiated an EMS Plan 1, which automatically sends five ambulances to a scene.
Langford said crews had extinguished most of the fire as of 7:35 p.m. and no injuries were reported.
This is at least the third time the Old Main Post Office has caught fire since it was shut down.