Police were called to the Carl's Jr. in Monterey Park around 9:30 a.m. after receiving a report that the unidentified man was breaking windows at the restaurant.
When he emerged from the fast food place, the Los Angeles County Sheriff's Department said in a news release they ordered him to drop what they described as a three-foot metal bar.
When he refused, they attempted to Taser him, the news release said. Police say he then swung the bar twice at an officer, causing the cops to open fire.
The man was shot five times, KTLA 5 News reported. He was rushed to the hospital, where he was pronounced dead.