Sevier County, UT- A Clinton family camping in a cargo trailer near Fish Lake suffered severe burns when a leaking propane heater erupted in flames Sunday.

The family of five, ages 40 to 7, all received first- to third-degree burns to their faces and extremities, according to the Sevier County Sheriff’s Office. Three were flown by helicopter to the University of Utah burn center, one went by ambulance, and another was treated and released at the scene.

The father told state fire investigators he had just struck the igniter on a propane heater when the entire trailer burst into flames, the sheriff’s office said. The explosion caught several items on fire, melted other items and separated a seam in the roof.

Investigators found a coupling to the propane bottle hose that was leaking propane, according to the sheriff’s office.

The Richfield emergency communications center received a call at 6:45 a.m. but the call was lost before a location or information could be obtained. It received another call at 6:57 a.m. reporting a trailer fire near Mytoge Road just south of Fish Lake.

As Sevier County EMTs and deputies and the Koosharem and Richfield fire departments headed to the scene, the family was driving to Richfield in their truck. Emergency medical workers met the family on the highway and transported them to Sevier Valley Hospital. Family members were treated there before being taken to the burn center.