Man killed by security guard after bizarre stabbing attack at Palmdale McDonald's

"[The officer] is still shaken up," the security manager said.

A 29-year old man was shot and killed by a security guard after slamming his car into a California fast food restaurant, stripping off his clothes, running into another restaurant and stabbing an elderly man, police said.

On Sunday evening, the Hispanic male, who has not yet been identified by authorities, crashed his car into a Palmdale Carl's Jr. before disrobing and running into a McDonald's across the street, according to ABC station KABC.

A security guard nearby witnessed the suspect stripping down and running with a knife in hand, according to Juan Paiz, owner of the private security firm that patrols the shopping complex.

"We're trained to remove the threat from the public," Paiz told ABC News, explaining the officer was trying to get the suspect to follow him out of the restaurant after he attacked an 88-year-old Hispanic man.

"As [the officer] was backing out, the suspect then went after him with the knife. Unfortunately, the security officer tripped while he was backing out of the restaurant," Paiz added. The officer, pinned down by the attacker, then pulled the trigger.

"All I hear was 'pop pop pop,'" one witness told KABC. "So I ran over here, I see this guy on the ground."

The suspect died later at the hospital, according to the Los Angeles Sherriff's Department, which added the elderly man was transported to a local hospital where he was listed in stable condition.

"[The officer] is still shaken up," said Paiz, applauding the officer for risking his life for others.

"This type of stuff can happen anywhere. We train to deescalate and settle everything without any kind of force. But sometimes stuff happens so quickly there's just no time," he added.