A broken circuit panel on the third floor caused a brief evacuation of the Transwestern 2 building, 490 N 31st St., Tuesday morning in Billings.
"We heard a loud bang and the lights went off," said Lauri Brogan, an employee on the third floor where the panel burst. A burned plastic smell could be detected throughout the floor.
Several fire engines and a Battalion Chief were called out at about 8:30 a.m. in case a fire needed to be extinguished but they were quickly called off when they were not needed, said Billings Fire Department Captain Bret Tormahlen.
The smoke came from a circuit panel that burst after being exposed to water, he said.
The water had been dripping from a fourth floor sink that was overflowing, but the building's maintenance crew was quickly able to switch off the power and prevent a fire.