Tal Ehlers, Uintah County emergency manager, estimated the evacuation which was in place until about 6:30 p.m. included about 30 homes.
Kiera Layton, her fiance, Nick Lee, and his family were awake at their Naples home, about four miles from the site, when they heard a thundering boom.
"It shook our whole double wide trailer," she said. "We thought an airplane had dropped or a bomb had gone off."
Layton, 23, turned on a police scanner in the home to find out what was happening and then jumped into her car with Lee's sister to watch firefighters fight the blaze from a few hundred feet away.
"Driving toward it, all you could see was this big mushroom cloud," she said. "We could see the buildings were all on fire. I got out of the car and you could hear it roaring."
Firefighters from three agencies fought the flames for several few hours, but not before the blaze had destroyed an industrial building, severely damaged eight others and moderately damaged three homes, according to a news release.
"I was doing some computer work [in my den] when it happened," said Treven Birchell, who lives about 12 miles from the site. "It was just a big boom, the windows rattled, the dogs started barking. ... It's amazing that no one was killed."
The American Red Cross had placed a temporary shelter plan on standby at Vernal Middle School, 712 W. 100 South, for anyone displaced by the fire and evacuation.
The state's fire marshal has sent investigators to help determine what happened, though early signs indicate it was a gas or propane explosion, Ehlers said. No one was at the site when it erupted.
Adler Hot Oil Service is a Vernal-based company that sells hot oil trucks for cleaning oil and gas processing equipment, heating fracturing fluids and pumping fluids down well bores, among other applications, according to their website. The company could not be reached for comment.
In November 2010, a fire damaged the same Adler Hot Oil Service building that was destroyed on Saturday. Several explosions and a subsequent fire injured two people and caused more than $2 million in damage.