Idaho teen killed in Garden Valley fire re-entered home. Cause ‘undetermined’
Authorities have been unable to determine the cause of a deadly fire in Garden Valley.
The fire on May 4 destroyed a mobile home and killed a 15-year-old boy at 12 Summer Drive near the Terrace Lakes Resort, Boise County Sheriff Scott Turner told the Idaho Statesman.
Friends and family identified the victim in a GoFundMe as Tristan Stephens, who was a ninth-grade student at Garden Valley High School.
A witness saw Stephens flee the area before he returned and re-entered the home through the front door, the Idaho Department of Insurance said in a news release.
“Due to the speed and intensity of the flames, the teen became trapped inside and succumbed to the smoke and fire before emergency crews could arrive,” the release said.
Stephens lived with his grandmother, Marla Warner-Smith, according to the fundraiser.
“There are no words to fully capture the pain and shock our family is enduring,” the fundraiser said. “Marla is now left with nothing, trying to rebuild her life from the ground up while grieving the loss of her grandchild. Her homeowners insurance was unexpectedly canceled so there is no financial safety net to fall back on.”
Money raised will go to Warner-Smith to pay for funeral and memorial expenses; basic necessities; temporary housing and longer-term relocation; replacing lost household and personal items; and emotional recovery, according to the GoFundMe.
Cause of fire ‘undetermined’ after extensive damage
The Idaho State Fire Marshal’s Office, which began investigating the night of the fire, said it has ruled the blaze as having an “undetermined cause,” and the case remains open. The office said the fire’s destruction made it too difficult to verify how it began.
“Because of the extensive damage, we can only speculate on the fire’s origin,” State Fire Marshal Knute Sandahl said in a statement. “We do know the porch contained numerous boxes and personal items, as the homeowner and her grandson had recently moved in.”
A neighbor called 911 at 10:04 p.m. after seeing flames on the home’s back porch, according to the Idaho Department of Insurance. Law enforcement agencies and fire units from Garden Valley, Horseshoe Bend and Lowman responded.
“The witness reported that the fire spread rapidly, climbing toward a snow roof structure and quickly consuming the entire residence,” the insurance department said.
When firefighters arrived, the home was “fully engulfed in flames,” and the heat exposure caused a nearby residential propane tank to begin “producing a dangerous stream of fire,” according to the insurance department.
Crews focused on cooling the tank to prevent an explosion.
At the time, residents took to social media to report hearing explosions and noises. State officials said those sounds were “later identified as coming from smaller, camping-size propane bottles.”
Fire departments extinguished the fire by 2:30 a.m. May 5, Turner said.
This story was originally published May 13, 2025 at 3:48 PM.
