PALMDALE (CBSLA) — A naked 29-year-old man brandishing a knife was shot and killed by a security guard after a bizarre series of events Sunday afternoon in which he reportedly plowed his car into a Palmdale fast food restaurant, and then stabbed an elderly man at an adjoining eatery.

The incident played out at around 4:30 p.m. in the area of 25th Street and East Avenue S.

It began when the suspect, described initially as a shirtless Latino man, crashed his car into into the wall of a Carl’s Jr. restaurant, according to the Los Angeles County Sheriff’s Department. He then got out and ran across the street to a nearby McDonald’s, during which time he undressed completely.

Deputies said the man, now naked, entered the McDonald’s and stabbed an 88-year-old man who was eating with his grandson.

As the suspect was coming out of the McDonald’s, he was confronted by an armed security guard, the sheriff’s department said. When he tried to assault the guard, the guard shot him at least once, hitting him in the upper torso, deputies said.

Both the suspect and the stabbed customer were taken to local hospitals. The suspect was pronounced dead, while the stabbing victim was listed in stable condition and was expected to survive, officials at the scene told CBS2.

The guard was unhurt.

Witnesses said it all happened so fast.

“I see a man standing right here,” witness Irvin Diaz told CBS2. “And all I heard was ‘pop, pop.’ And I came over and saw this man on the ground. He was naked, holding his stomach.”

A knife was recovered at the scene. The suspect’s name was not immediately released. Deputies are investigating the cause of the accident and are searching for a motive.