Wessington Springs, SD- State fire officials say a leaky propane line likely is the cause of an explosion that injured one man and destroyed three homes last week.

State Fire Marshal Al Christie says a propane line in the crawl space of Darrick Van Dyke’s residence apparently was leaking and found an ignition source.

Van Dyke was flown from the Wessington Springs airport to Hennepin County Medical Center in Minneapolis. His family says he sustained third-degree burns on his legs and remains hospitalized.

Van Dyke was the only person injured in the blast.

The Van Dyke home and two adjacent homes — both unoccupied — were destroyed by the explosion.

Christie says the propane could have come into contact with various ignition sources, such as a furnace pilot light or static electricity.