A blast at an oil refinery near Yellowstone Highway on Tuesday was traced to a furnace being used to heat a crude oil processing unit.
The explosion at the Sinclair Casper Refinery occurred at about 2:02 p.m. Tuesday. Witnesses said the blast could be felt three-quarters of a mile away.
Mike Achacoso, plant manager of the refinery, said no injuries were reported and everyone was accounted for after the "small explosion." One employee was taken to Wyoming Medical Center as a precautionary measure, according to Achacoso.
The cause of the blast is still under investigation.
Lt. Stew Anderson, head of Natrona County Emergency Management, said that when he arrived at the scene no fire or smoke was visible.
The explosion was an isolated incident and no off-site impacts were reported, Achacoso said.
"I'm going to do everything in my power to prevent something like this from happening again," he added.
The Sinclair Casper Refinery, located at 5700 E. Yellowstone Hwy., employees 120 people and produces roughly 25,000 barrels of gas and diesel each day.
Responding to the blast Tuesday were crews from the Evansville Fire Department, the Casper Fire Department, the Evansville Police Department, Wyoming Medical Center, Natrona County Emergency Management and the Natrona County Sheriff's Office.