OMAHA, Neb. (AP) — Investigators have determined the cause of a fire at an Omaha auto repair garage that sent one person to the hospital.

Omaha Fire Battalion Chief Tim McCaw says fuel vapors ignited by a water heater caused the fire Monday at a building owned by A-1 United Heating and Cooling, near the northeast corner of 50th and F streets. Fire officials closed off streets in the area to contain the blaze.

Dispatchers say the injured person was taken to Nebraska Medical Center in critical condition for treatment of burns. The person’s name and current condition haven’t been released.