Slag from a welding torch sparked a three-alarm fire at the ZCMI Center Saturday morning.
The fire was contained in a third-floor attic area above the food court, and at least 200 people were evacuated from the mall.
The fire was ruled to be accidental, said Dennis McKone, administrative assistant to the Salt Lake City fire chief.
About 11:30 a.m. someone inside the mall called to report black smoke coming from the space between the mall and the building to the west — a Zions Bank under reconstruction.
That was before fire alarms kicked in to notify the fire department.
"It was a good thing they called us when they did," McKone said.
The three-alarm designation, a precaution for the downtown buildings, meant three ladder trucks, nine engines and about 65 firefighters responded to the scene while Main Street and South Temple were shut down around the mall until 2:30 p.m.
When firefighters arrived, white smoke was drifting from the roof of the mall onto South Temple. Mall staff members told patrons to leave the mall because there was a fire.
But no fire alarms were audible.
Once patrons were outside the mall, a firefighter told them to leave the block, too.
Michael and Pauline Canale of Layton were eating lunch in the food court when they noticed smoke rising above the glass roof.
Michael, a retired firefighter, knew something was wrong and was surprised he didn't hear an alarm. So the Canales left the mall.
A short time later, food court employees got the word they were to leave. Some wanted to protect food, but there wasn't time.
Smoke began to enter the food court when some of the glass panes broke.
Amalia Mendoza, who works at Blimpie, said she was glad to get out of the food court because she couldn't breathe.
The mall reopened by 2:30 p.m., but the food court remained closed Saturday while Utah Disaster Kleenup pumped water from sprinklers and firehoses out of the mall.
Restaurant employees were allowed back in to prepare food and clean up.
McKone said he expects the food court to reopen Monday for Labor Day.
He estimated damage to the mall, which was mostly water damage, to be about $500,000.
It appears the slag from the welding torch ignited plywood that had been placed over the glass panes of the food court. The fire was concentrated in the space between the two buildings, but perhaps as many as six fire sprinklers turned on when the fire got inside the mall, McKone said.
He called it a hard place to fight a fire.