Atlanta fire investigators Wednesday were trying to determine if an overnight fire that heavily damaged two homes was caused by a gas explosion.

The fire broke out in an unoccupied home on Mobile Street in northwest Atlanta, and spread to a house next door where about a half-dozen people lived.

All the residents got out safely, and no injuries were reported, Atlanta fire Battalion Chief Bryant Tate told Channel 2 Action News.

Bryant told the station that when firefighters arrived, they found the first house heavily involved in flames. Bryant said radiant heat caused the second house to catch fire.

He said crews initially had “some issues getting water” from the closest hydrant to battle the blaze.

“We had water but it wasn’t enough water to do what we needed to do,” Bryant said. He said crews found a second hydrant nearby that had sufficient pressure.

Bryant told Channel 2 that there were “reports of a gas explosion,” but that that hadn’t yet been confirmed. Investigators from Atlanta Gas Light were on the scene of the fire.

Staff photographer John Spink contributed to this article.