LEWISTON – An official blamed a fire in a Pierce Street apartment building Saturday on condensation that dripped from a third-floor air conditioner and shorted out a box fan in a window one floor below.

Lewiston fire investigator Peter Morrell said water dripping from the third floor fell close enough to the second-floor fan to get sucked into the unit. The fan caught fire but continued to spin.

“It ended up blowing fire into the second-floor bedroom,” Morrell said. “I’ve never seen anything like it.”

Fire crews from Lewiston and Auburn responded to reports of the blaze at 134 Pierce St. just before 7 p.m. Saturday. Crews contained the fire to the back bedroom of apartment No. 2 on the building’s second floor.

“I don’t even think anyone was home at the time,” Morrell said.

Neighbor Richard Labonte of 126 Pierce St. said he was sitting in his living room directly across a parking lot from the building when he noticed the flames. “It scared me, because I didn’t know if anyone was in there,” Labonte said. “I know there are kids in that building, and I was scared for those kids.”

No injuries were reported. Morrell said he was still investigating the fire’s cause.