Boise fire officials say the hot sun and record setting 105-degree heat Sunday caused a large propane tank to vent and explode, destroying two homes Sunday in East Boise near Barber Park.
It took firefighters more than two hours to knock down the flames which razed two homes on Iriondo Way because the explosion also ripped out a nearby natural gas line, according to Boise fire reports.
The fire was so intense — and the temperatures so oppressive — that about half of all Boise city firefighters on duty Sunday battled the blaze at some point during the evening as crews rotated, said Boise Fire Assistant Chief Dave Hanneman.
Investigators have determined the fire was accidental.
The 3-alarm fire was called into Ada County dispatchers at 5:35 p.m. Sunday.
The couple who lived at 4013 Iriondo Way initially believed the explosion came from the neighbor’s air conditioner, but several more explosions followed, and the Boise Fire Department also reported a natural gas leak at the scene.
Officials have determined that a 25-gallon propane tank sitting between the two homes, at 3987 and 4013 Iriondo Way, and next to a small camp trailer got so hot in the sun that it began venting some gas — a safety measure which begins when the gas inside gets too hot and expands.
Propane is heavier than air, so fire officials suspect the gas then began to accumulate in the area between the two homes, where the gas eventually drifted into an ignition source — like a spark from an air conditioner or a pilot light — when it caught fire.
The propane tank, which belonged to the homeowner at 3987 Iriondo Way, then exploded and caught the homes on fire, according to reports. The blast also ripped out the gas line to one of the homes, so that gas fueled the flames as well, Hanneman said.
The gas line was turned off by 7:30 p.m. Sunday, Hanneman said. Fire crews didn’t leave the home until after 10 p.m. Sunday, and fire crews checked through the night to make the fire was out, according to reports.
Both homes were destroyed, although some of the items inside may be salvageable, according to reports.
The families who lived in both homes are being assisted by the Idaho Red Cross.