BENICIA (KPIX) — A contract employee died at Valero’s Benicia refinery Friday night, a company spokesperson has confirmed.

According to Valero, an investigation is being conducted to determine the cause of death and whether it was work-related.

The contractor died around 10:30 p.m., the spokesperson said in an e-mail sent to KPIX.

The Vallejo Sun has reported that a male worker fell six stories to his death.

Valero is cooperating with the deceased worker’s employer, Cal OSHA and other state and local agencies participating in the investigation.

“Our thoughts and prayers are with the contractor and their family during this time of loss,” Valero’s spokesperson said in the e-mail.

The refinery in Benicia was acquired by Valero in 2000 and processes crude oil into gasoline, diesel fuel, jet fuel and asphalt.