As East Bay residents recovered Tuesday from the effects of a massive fire at the Chevron refinery in Richmond on Monday night, the head of emergency services at the facility provided updates on the blaze.

Mark Ayers said a hydrocarbon leak was initially detected in the No. 4 crude unit about 4:30 p.m. Monday. He said the leak was minor. When asked why Chevron didn’t notify county health officials, Ayers said there were “no thoughts it would impact the community.”

After the leak was spotted, workers began assessing it and putting together a plan to stop it, Ayers said. The leak grew larger at 6:30 p.m., and employees, trained to avoid putting themselves at risk, left the area, he said.

As it expanded, it created a “big vapor release and ignition,” Ayers said.

Residents in the area reported hearing explosions around the time the fire started, but Ayers didn’t address those reports.
The cause of the leak remains under investigation.

Mayor Gayle McLaughlin said she has been hearing from many angry residents.

“I really want ... Chevron to be forthright in providing all the details of their investigation,” she said.