CACHE JUNCTION, Utah (ABC4) — Officials confirmed on Monday that a propane gas leak caused the house explosion in Cache County that killed one and critically injured two last week.

Cache County Fire Chief Rod Hammer says the investigation has revealed a gas leak in the fuel line system, leading propane to pool in the basement of the house. The explosion reportedly occurred when propane gas in the basement came in contact with an ignition source.

“Propane gas is heavier than air and will pool in low areas such as basements,” Hammer said. “Should you smell natural gas or propane in your home, it is important that you call 911 and have the fire department investigate.”

Hammer reminds homeowners to cover gas meters and regulators as snow and ice sliding off roofs can cause damage to these types of equipment. Any repairs or leaks in the gas systems should always be done by qualified experts.

According to Dominion Energy, here are some signs of a natural gas or propane leak:

  • A rotten egg odor.
  • Discolored or dead vegetation over or near the pipeline.
  • A hissing, whistling, or roaring sound near a gas appliance or pipeline.
  • Dirt or debris blowing into the air; persistent bubbles in water-covered areas.
  • Flames (if a leak has ignited).

The house explosion occurred near 5670 N State Route 23 at about 6 p.m. on Thursday, March 9. Officials confirmed one man is dead and two other individuals were critically injured.

The man who died in the explosion was identified as John Mullin.

His wife, Caryn Mullin, was transported to the Logan Regional Hospital with multiple fractures and burns to her body. She has been reportedly transferred to McKay Dee Hospital for additional care.

Their son, Joshua Mullin, was transported to the Cache Valley Hospital as well. Officials say he suffered multiple burns on his arms, chest and face.

Members of the Mullin family are reportedly professional dog breeders as licensed by the county. Officials say there were 30 dogs on the property in a separate building at the time of the explosion and another 16 dogs were in the house.

Firefighters reportedly recovered five of the 16 dogs five hours after the explosion. They have been taken to the New Vision Intake and Animal Shelter for treatment. Of the five dogs, officials say three are in critical condition and two are in good condition. All the other dogs have been taken care of by other family members.

“Our sincerest condolences to the family of the victims involved in this incident,” said Lt. Mikelshan Bartschi with the Cache County Sheriff’s Office.