A major collision occurred in the middle of State Route 54 in Bonita near the Briarwood Road exit, shutting down all westbound lanes Saturday evening, according to California Highway Patrol.
Two women in a Ford Mustang and a man in a Lexus crashed in the middle of the freeway around 8:30 p.m. A truck then slammed into the Lexus.
The truck and the Lexus flipped over, sending both cars further down the highway.
The male in the Lexus had taken his seatbelt off before being hit again by the truck and became trapped in his car so that firefighters had to extricate him from the wreckage, CHP said.
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The man was rushed to a nearby hospital with major, possibly life-threatening injuries. He may lose his leg, firefighters said.
The male driver of the truck was able to remove himself from the car and was badly cut on one of his hands, CHP said.
Both women in the Mustang were not injured.