Authorities suspect that a crash that left three family members and a good samaritan dead may have been caused by a drunk driver.

A white Nissan truck slammed into two vehicles that were pulled over on a California freeway, ABC News reported.

A woman, her two children and her mother had pulled over when the engine of their Honda overheated, and a pickup truck pulled over to help, according to the network. The female driver and her mother exited the vehicle just before the crash and were standing with the good samaritan.

The impact was so strong, it crushed the entire backseat of the Honda, killing the two children in the backseat, ABC reported. It sent the pickup across the other side of the highway and killed the good samaritan and the driver’s mother, according to the network.

Police told ABC they found open cans of beer in the white Nissan, and stayed with the driver after he was taken to the hospital. He is being held at the hospital pending toxicology reports and has refused to speak to police, according to the report.

The mother of two children survived and is in the hospital with serious injuries. Her husband, whom she had called for help earlier, had arrived and discovered the scene, police told ABC.