A fire engulfed part of a Chevron oil refinery in Richmond Monday evening, sending large plumes of smoke and chemical fumes into surrounding residential areas. Large plumes of dark smoke with a pungent smell of chemicals hovered over Richmond at sunset, as fire sirens wailed and streets were cleared.

A fire engine responds to the Chevron refinery fire.

At a press conference held Monday night, Richmond Refinery General Manager Nigel Hearne told journalists that firefighters were still fighting the blaze at the plant, and that a small leak in the diesel processing unit had grown and caught fire. According to Chevron spokesperson Melissa Ritchie, the fire started at Richmond Refinery’s No. 4 Crude Unit. Hearne said had grown and caused the explosion at 6:15 pm.

Hearne said fighters and engineers at the plant were using nitrogen to push fuel through the pipes, and warned that the fire could burn all night.

As fire sirens wailed over one of the refinery’s cafeterias, in which a press conference was hastily arranged, Hearne offered an apology to the thousands of Richmond residents who had been forced indoors as a result of the smoke from the fire. Earlier in the evening, the Contra Costa County Health Services Department had issued a shelter in place warning for Richmond residents, advising that residents remain inside, shut windows and doors, make sure vents are closed, turn off ventilating and air conditioning, and bring pets indoors.

“As you can see, we’ve made significant progress, and we’re still in the process of controlling the fire,” Hearne said, adding that the priority was extinguishing the fire, which he said had caused only a minor burn to one of the oil giant’s employees. Earlier in the evening, Ritchie had told Richmond Confidential that one worker had suffered a burn on the wrist.

The sky appeared yellow due to the smoke in the air.

Hearne said the Chevron was collaborating with local government agencies to investigate the cause of the fire. Earlier, Chevron released a statement saying was cooperating with government agencies at the plant. “We have put in place comprehensive plans and procedures to respond to situations like the one we are facing,” the statement read. “We are working with all appropriate local authorities.”

Chevron has announced that it will host a town hall meeting on Tuesday, August 7 at 6 pm at the Richmond Memorial Auditorium.

You can read our previous coverage, with photos submitted by readers, here. You can read our full archive of Chevron-related stories here.