Two people died and two others were seriously injured in a house explosion July 31.

Delbert and Virginia Hurt of Pilot Knob died in their home after their home exploded and caught fire.

Their son, Lawrence, and a home health care nurse, Lisa Pulley, reportedly received serious injuries in the explosion. Lawrence, who suffered burns and a broken hip, was able to pull the nurse from the fire.

The state fire marshal’s office has not determined what caused the initial explosion. The office is looking at a water heater.

Officials said it is believed the initial explosion was caused by propane gas. That explosion caused the walls and roof to collapse. Two smaller explosions may have been caused by oxygen tanks that were in the house.

The residence was located at Snow Hollow Lake Road near Route N in Iron County.