A man and a woman were decapitated Sunday in a car wreck on the 5 Freeway, officials with the California Highway Patrol said.

Authorities said alcohol and excessive speed may have been factors in the crash, which occurred just before 1 a.m. in the southbound lanes near the 405 Freeway exchange in Sylmar.

The man was driving a 2010 Lexus sedan with the woman as the passenger when they slammed into the back of a big rig that was parked on the right shoulder of the freeway, CHP officials said in a statement.

The car “failed to maintain the curve in the roadway before traveling out of control” and crashing into the big rig.

Video from the scene captured by KTLA-TV showed the mangled wreckage of the car.

The driver of the big rig, a 35-year-old man who did not wish to be identified, told the outlet that the silver sedan caught fire after the collision.

“All I felt was a major hit,” he said. “I felt like I was hit by a semi.”

The two who were killed — a 38-year-old man and 22-year-old woman — have not been identified. They were pronounced dead at the scene, officials said.

The driver of the big rig was not injured in the collision.