An explosion caused a fire at a Chevron oil refinery in Wales on Thursday, killing four contractors and seriously injuring another worker, the company said.
Chevron spokesman Sean Comey said that the blaze was extinguished. It wasn't immediately clear what caused the explosion at the refinery, which employs 1,400 workers.
Greg Hanggi, the refinery general manager, said in a statement that the loss of the four workers was "devastating."
"We will take every step possible to determine the series of events that led to this tragic incident and ensure that any lessons learnt from it will be integrated into the business and shared with our industry partners," he said.
A fire department spokesman confirmed that five engines responded to the blaze at around 6:20pm (1720 GMT; 1.20pm EDT). The spokesman declined to give his name, citing company policy.
In March, Chevron agreed to sell the Pembroke refinery along with other marketing and logistics assets throughout the UK and Ireland to Valero Energy Corp. for $1.73 billion.
Chevron Corp. is based in California.