Fullerton police used a bullhorn to awaken two men in a car early Friday morning, and at least one opened fire, unleashing a volley of shots at officers, who shot back, killing one man and wounding the other.
Authorities said they did not know what led the men to open fire.
No officers were wounded.
The incident began when the driver of an Orange County Transit Agency bus called police at 2:30 a.m. to report that a gray car was sticking out of a driveway, partially blocking the southbound lanes of Harbor Boulevard near the 91 Freeway.
When police arrived, they saw the two men in the car either asleep or unconscious, the driver holding a shotgun in his lap and the passenger a handgun, said Fullerton Police Sgt. Linda King.
After reinforcements arrived, the officers, using a bullhorn, ordered the men out of the car. The driver awoke, immediately started the car and accelerated, while the passenger opened fire, King said.
The car crashed into a police barricade and the passenger and perhaps the driver continued firing until they were wounded, King said.
The passenger, Arthur Kenneth Gallardo III, 28, of Fresno, was taken to UCI Medical Center in Orange where he was uncooperative with detectives, King said. The driver's name was not released pending a coroner's investigation.
Police were attempting to determine why the men were in Fullerton and whether they were under the influence of drugs. Fullerton police had never had contact with them, King said.