Residents who attended a Richmond town hall meeting one day after a refinery fire cast a black plume of smoke over their city expressed one emotion toward Chevron: rage.

In a rowdy expression of frustration and anger, more than 500 residents crowded into Richmond Memorial Auditorium, where people shouted down Chevron and Contra Costa County public health officials on hand to answer questions about the accident.

The question asked most often was, "What are we breathing?" Residents were repeatedly unsatisfied each time a public health official said inspectors didn't know because they were still analyzing the data.

For some, the venting and verbal stoning of Chevron was a much-needed outlet for people who had waited all day for answers - and in the end were provided few.

General Haymon, 60, a pastor who lives in Richmond, said the public display was necessary to blow off the steam of years of accumulated anger toward one of the city's largest employers.

"The more people who show up and the rowdier they are help get the message across this cannot happen again," Haymon said. "I don't care how rowdy people get, these guys have got to get the message."

At times, people jumped on stage to shout their opinions; a few people were escorted out by police.

Often when Chevron refinery General Manager Nigel Hearne spoke, he was met with extended boos and catcalls of "liar!" Residents held signs that read, "How many more 'accidents'?" and "Chevron out of Richmond."

Michael Bracy, 60, a construction worker, said he attended the meeting to get answers, but left frustrated by the antics of the outraged.

"Everyone makes mistakes," Bracy said. "Chevron is not God. I'm not mad about this. People need to calm down and listen to what Chevron has to say."

Chevron's Hearne reiterated an apology issued by the company.

Truck driver Greg McClain, 47, of Richmond said the oil company needed to hear out residents' frustrations, and residents needed to do their part as well.

"This stuff with Chevron has been going on as long as I remember," he said. "Chevron never seems to get the message. Chevron has to take a stand. And we, as the people of Richmond, have to follow this up."

Carolyn Jones and Justin Berton are San Francisco Chronicle staff writers. E-mail: carolynjones@sfchronicle.com, jberton@sfchronicle.com