A fire caused smoke damage and an hour-long evacuation at the General Motors plant, according to Southwest Allen County firefighters.
The fire was reported about midnight Friday at the plant, 12200 Lafayette Center Road. A spark from a welding project had entered a room filled with air filters, firefighters said.
The body and paint shop at the plant was shut down for about an hour because of smoke, firefighters said.
Five security officers working at the plant were treated at the scene for smoke inhalation.
Amanda Iacone of The Journal Gazette contributed to this report.