Firefighters spent an hour and a half battling a blaze on the 13th floor of the old Federal Reserve building in downtown Minneapolis on Tuesday afternoon.

No injuries were reported at the building, which was under renovation, and construction work on the site commenced shortly after firefighters extinguished the blaze.

“There are indications that the fire was started by welders in the building,” Deputy Fire Chief Harold Berffle said. “The firefighters had to cut into the steel wall to get to the flames.”

Due to excessive heat and height, the fire was more difficult to put out, Fire Chief Don Leedham said.

“We had to have relief crews to take over when the heat and conditions were too intense,” he said.

There was no water in the building while it was under construction. Firefighters ran hoses from the street up to the blaze.

“We had to advance hose lines 350 feet from the bottom to put out the fire,” Leedham said.

The fire earned four-alarm status, which brought 15 fire trucks and about 60 firefighters to the scene, Berffle said.

The Federal Reserve building, on the corner of Washington and Marquette avenues, is eligible for the National Register of Historic Places. The building was never listed due to the long process of registering, including a state review board evaluation.

The building is known for showcasing post-World War II architecture.

Maggie Hessel-Mial welcomes comments at [email protected]