A fiery explosion shook a Heber City neighborhood Monday and left nearly one-third of the city without power when highly pressurized tanks burst inside the shed of an oxygen-supply business.

"They were like missiles going off," Heber City Police Chief Ed Rhoades said. "It was like nothing I've ever seen."

The vibrations generated from the explosions of 40 steel oxygen tanks, which are pressurized to 20,000 psi, broke windows a block away and triggered car alarms several blocks away.

Nobody was injured during the nearly hour-long series of ground-rattling explosions that sent neighbors into a panic as debris as large as 2-by-4 boards rained from the sky 100 yards away, Rhoades said. Smaller debris such as paint chips fell a quarter-mile away, and responders found oxygen-tank knobs that had shot and become entrenched in a lawn a few homes away.

"We think we really dodged a bullet here," he said. "For this to happen and there be no injuries is really dodging one."

Though they have yet to assess the total damage from the explosion, the building is a total loss. Rhoades said discerning the final damage will be difficult, with the various elements they have to consider.

"There was so much damage to windows and stuff around the building, and I don't what the structure would cost or what kind of equipment he had. There were three or four vehicles. There's just a number of things that will make that hard to figure out."

Wasatch County and state fire authorities have yet to determine what caused the fire that turned an actively operating shed at Hicken Oxygen Co. into a mound of melting metal.

The fire, which started about 4:16 p.m., burned three nearby cars, but firefighters saved several nearby buildings, which stood as close as 10 feet away from the blazing structure, Rhoades said.

He said that while credit can be given to a "very responsive" fire department, the fact that there were no other buildings affected and no injuries was "very, very lucky."

About seven emergency agencies responded to what many characterized as a miniature war zone, and authorities hope to identify a probable cause for the fire sometime today.

Contributing: Emiley Morgan

e-mail: jhancock@desnews.com