A fire that caused $50,000 in damage to a four-unit building at Edgwood Homes Tuesday night — and even more damage when it rekindled Wednesday morning — was caused by flooring workers who started a closet wall to smolder, Lawrence’s fire chief said Wednesday afternoon.

“The fire originated in Apt. 152 in the west wall in the closet,” said Jim McSwain, chief of Lawrence-Douglas County Fire & Medical.

“The cause was workers heating floor tiles with a propane torch to loosen them,” McSwain said. The torch started the wall to smolder, which the contractor did not detect., he said.

“Then they left and it continued to grow and grow until it was discovered,” McSwain said.

McSwain said he had no new estimate on the damage caused to the four-unit, city-owned building, located in the 1600 block of Haskell Avenue.

Firefighters were contacted through a 911 call about 8:19 p.m. Tuesday and 25 department members responded. They found fire and smoke from the east end of unit of the one-story four-plex.

The two units on the west side of the building received heavy smoke and heat damage. Firefighters declared it under control at 9:34 p.m.

McSwain said a member of the department stayed at the scene overnight and reported that the fire had rekindled about 5:30 a.m. He said it was brought under control at 6:20 a.m.

âÂÂA rekindle is not a good thing,â McSwain said. âÂÂSometimes they just smolder and smolder and smolder for hours, then catch fire again.âÂÂ

About 20 to 25 firefighters responded to the second blaze.

âÂÂIt very heavily damaged the building,â McSwain said.

He said it appeared that the fire may have run through the attic that adjoins all four apartments.

“We don’t know where the spark was that rekindled it,” he said. Investigators couldn’t tell if it reignited in the wall or in the attic.

Fire & MedicalâÂÂs occupant services unit and the American Red Cross helped 11 people who lived in the apartments find other places to stay Tuesday night.