Chattanooga, Tenn., fire officials will investigate whether lightning sparked at least three fires.
Fire Department spokesman Bruce Garner said the fires broke out about 10 p.m. Tuesday as a severe thunderstorm rained lighting on the city.
In the most serious incident, firefighters arrived to find a four-unit townhome building enveloped in flames. Damage was extensive. At about the same time, fire units were called to another house fire and blaze in a commercial building.
A witness told fire officials lighting struck the house and firefighters arrived to find flames in the attic. Employees who were in the commercial building reported a flash and what sounded like an explosion before the flames erupted.
There were no civilian injuries. One firefighter was treated at the scene for heat exhaustion.