An office and storage building belonging to a south-side school district was heavily damaged by fire late Friday night.

Crews were dispatched at 11:38 p.m. to a building fire in the 5000 block of South Liberty Avenue in the area of West Irvington Road and South 12th Avenue west of El Pueblo Park.

The building is a closed school that is now used for storage and office space, said Mary Veres, spokeswoman for the Sunnyside Unified School District. S.T.A.R. (Students Taking Alternatives Routes) Academic High School is on the same property, but was not impacted by the fire.

Multiple calls were made to 911 reporting smoke and flames coming from the school property, said Capt. Barrett Baker, spokesman for the Tucson Fire Department. As they approached the neighborhood, responding crews reported seeing a large plume of smoke.

“The initial engine company arrived three minutes after dispatch and advised all units that the building had a large fire that was already coming through the roof of the school,” Baker said of the two-alarm blaze.

An eight-person “attack team” pulled hose lines to the door and forced their way inside the brick building, but a safety officer monitoring the blaze from outside called them back out of concern the burning roof might collapse under the weight of several large air conditioning units, Baker said.

“That whole roof was on fire,” Baker said. “Usually we get up there and cut the hole so the smoke billows out. But this one ventilated itself. It burned so long it burned through the roof.”

Firefighters continued battling the blaze from the exterior and “a large master stream of water was set up to extinguish the fire from above by pouring thousands of gallons on water on it from the extended ladder,” Baker said

Crews also pulled several hose lines to an inside courtyard to gain better access to the fire.

It took 40 firefighters a little over an hour to bring the blaze under control.

The origin and cause of the fire remain under investigation, Baker said late Saturday afternoon.

Classes at neighboring S.T.A.R. Academic High School will not be affected, Veres said.