A carelessly discarded cigarette Friday morning sparked a mattress fire in the loading doc of the Value Village Thrift store, 2700 N. Stone Avenue.

Photo courtesy of the Tucson Fire Department

A carelessly discarded cigarette caused $20,000 in damage when a stack of mattresses on a thrift store loading dock caught fire Friday morning.

Though the fire was outside the Value Village Thrift Store at 2700 N. Stone Avenue near East Glenn Street, when crews arrived at about 10:45 a.m., there was a danger of it spreading inside, Capt. Chris Jurvig, spokesman for the Tucson Fire Department, said in a news release.

“Firefighters knew they had limited time to contain it since fire can double in size every minute,” Jurvig said. “The first arriving fire company made an aggressive attack and began extinguishing the blaze.”

Additional crews pulled hose lines inside as they searched the building and evacuated about 20 workers and customers. The ladder company controlled utilities and went up to the roof to check for fire spread and prepare for ventilation.

“Fire crews successfully stopped the fire from spreading into the interior of the structure. They were able to confine the fire to the exterior where a large pile of mattresses and other furniture had been burning,” Jurvig said.

It took 24 firefighters from nine units about five minutes from dispatch to bring the fire under control.

Damage is estimated at $20,000. The cause of the fire is under investigation.