INDIANAPOLIS – Investigators in the Indianapolis explosion that killed two people and decimated a neighborhood believe natural gas was involved and are focusing on appliances as they search for a cause, a city official said Tuesday.

Indianapolis Homeland Security Director Gary Coons made the announcement after the National Transportation Safety Board said investigators had found no leaks in the gas main or pipes leading into the house that exploded. The explosion Saturday leveled two homes and left dozens more uninhabitable.

Coons said his "investigators believe natural gas is involved" and were "recovering the appliances from destroyed homes to help determine the cause."