SUNRAY, Texas (AP) – An explosion rocked a West Texas refinery Friday, critically injuring at least three people and sparking a blaze that sent a huge black cloud billowing into the sky.

More than 400 workers were evacuated from the Valero McKee Refinery after the explosion, authorities said. No fatalities were reported, and the plant said all employees had been accounted for.

“The main thing is getting them away from there,” Moore County Judge Rowdy Rhoades said.

Paul Jenkins, fire chief in the nearby community of Dumas, said Valero’s fire brigade was fighting the blaze. The refinery was shut down after the blast, as were pipelines in and out of the facility, the company said.

Valero Energy Corp. said the fire was believed to have started at the refinery’s “propane deasphalting unit,” where fuel is processed at high temperatures. Witnesses said the smoke could be seen 60 miles away.

A nursing supervisor at University Medical Center in Lubbock, home of the regional burn unit, said one man was in critical condition and that two more were expected to arrive in critical condition. Patients were also expected in Amarillo.

Valero, the largest refiner in North America, operates 17 refineries, 16 in North America and one in Aruba. The McKee refinery, located in Sunray, is one of six in Texas and has a capacity of 170,000 barrels per day.

Sunray has a population of about 2,000.