A man died when he fell from a pickup truck after an apparent road-rage incident in Pasadena, officials said.

Men in two pickups had argued as they were driving on the Beltway 8 service road about 5:30 p.m. Wednesday, according to Vance Mitchell, spokesman for the Pasadena Police Department.

When they stopped at a red light, a man jumped out of one of the trucks, ran to the other pickup and broke out the driver's side door window, police said. He punched the driver several times. The driver called 911.

When the light turned green, Mitchell said, the two pickups left but they pulled into a nearby parking lot and stopped.

That's when two men leaped out of one of the trucks and ran to the other. One of them reached into the cab and grabbed the keys out of the ignition.

When the two men realized the driver was talking with a police dispatcher about the incident, they ran back to their truck. One got behind the steering wheel and drove away. The other tried to grab on to the back of the truck to get into the bed, but fell off and struck his head on the ground when the truck hit a curb. He died at the scene.

The truck's driver sped away. The road-rage victim remained at the scene, on Preston near Red Bluff. He was not seriously injured, Mitchell said.

What led to the initial confrontation was unclear.