Two firefighters were treated for heat exhaustion after battling an extra-alarm fire that started early Thursday on the 10th floor of a 22-story commercial building in the Loop, officials said.

Shortly before 4 a.m. Chicago fire crews were called to 5 S. Wabash Ave., a building also known as the Jeweler’s Center, said Fire Department spokesman Chief Frank Velez. The first crews arrived within five or six minutes and saw smoke coming out of an elevator shaft, indicating there was a fire on one of the upper floors, he said.

“There was heavy smoke inside, pushing down into the elevator shaft,” Velez said.

Firefighters checked stairwells and started climbing, eventually finding the fire on the 10th floor, Velez said. The fire was extinguished before it could spread to other floors, and fire investigators will determine the cause, Velez said, adding it was too early to tell how it began.

The two firefighters who were treated for heat exhaustion are expected to quickly recover, Velez said.

“Checking for civilians, we do have to climb all the stairs to make sure, so you’re doing 20 floors up and down,” Velez said. “That’s with 100 pounds of equipment when you’re climbing, that gets exhausting, quick.”

The fire was struck out just before 5:30 a.m. and no one else was hurt, he said.

“We got it extinguished right away and checked the 11th floor since heat rises. We opened the windows up and did some ventilation,” Velez said.

The early morning blaze closed several nearby streets and led to the temporary rerouting of nearby CTA bus routes. Check the CTA website for bus reroute information.

___

(c)2020 the Chicago Tribune

Visit the Chicago Tribune at www.chicagotribune.com

Distributed by Tribune Content Agency, LLC.