State fire marshal determines water heater caused Snow Dragon fire

EPHRAIM—A fire that destroyed Snow Dragon Chinese Restaurant in Ephraim earlier this month was caused by the failure of a natural gas water heater, according to an investigation by the Utah State Fire Marshal’s Office.

The fire was reported at approximately 1:30 a.m. Aug. 10 at the restaurant. The business was unoccupied at the time and had reportedly been locked by the manager at about 8 p.m. the previous evening.

A passerby discovered the fire, which was reported to be heavily involving the building and venting through the roof when firefighters arrived. Crews from the Ephraim and Manti fire departments responded.

While firefighters were dealing with the blaze, parts of the restaurant’s roof collapsed in the dining room. Debris fell on some firefighters, but no injuries were reported. Firefighters initially conducted defensive operations focused on the roof before moving inside the building. Investigators found the fire had spread above the ceiling and through the roof space.

Surveillance video from Ace Hardware, located directly north of the restaurant, also helped establish the fire’s progression.

According to the report by Utah State Deputy Fire Marshal Reed M. Thompson, investigators determined the fire originated in the mechanical space in the rear of the restaurant, near the kitchen preparation area.

“Fire patterns and greater material loss in the southeast portion of the roof helped investigators identify the area of origin,” Thompson said. “The investigation turned up evidence of significant damage to the restaurant’s natural gas water heater. The heater’s gas control valve was on, and its temperature control dial was set to the maximum setting.”

Investigators also found that the natural gas supply line to the water heater had been partially sheared at the threads. The report noted a corresponding fire pattern on a block wall and greater charring in the attic directly above the damaged gas line.

The fire marshal’s office concluded the natural gas water heater was the ignition source and that natural gas was the first fuel ignited.

Investigators also determined the water heater’s temperature and pressure relief valve and associated thermal expansion tank failed to relieve pressure created as the water heated. That mechanical failure, the report states, caused the vessel to shift violently, damaging the natural gas supply to the appliance and allowing gas to contribute to the fire.

Accordingly. the fire has been classified as accidental.

Investigators ruled out several other potential causes, including lightning, oily rags, construction equipment, lithium-ion batteries, propane and smoking materials. No electrical wire arcing was observed in the area of origin, and investigators determined several tripped breakers were likely the result of fire damage rather than the cause.

The investigation also found no evidence the fire was intentionally set. Because the restaurant had been locked and was unoccupied, firefighters had to use forcible-entry tools to gain access.

“There was no indication or observations that the fire was intentionally set within the area of origin,” Thompson said.