Garibay, an Antioch resident, was a passenger in a 1998 Dodge Durango with four friends when the crash happened.
The group had been driving from party to party in a heavy rainstorm. It was about 11:25 p.m. and they had just left one of the parties, where they had been drinking alcohol, Sgt. Diane Aguinaga said.
The SUV was headed east on James Donlon Boulevard when the driver lost control at Nightingale Drive and crashed into a retaining wall, causing the vehicle to flip onto its side, police said.
Garibay was pronounced dead at the scene.
The 18-year-old driver and two 16-year-old twin girls were taken to a hospital for treatment of various injuries, police said.
One of the girls had a spinal fracture and a severe head injury, Aguinaga said. She was listed in critical condition.
The girl's sister also had a brain injury, but was conscious and talking when she was transported to the hospital, Aguinaga said.
The driver had several broken bones and a concussion.
Another 18-year-old man was treated at the scene for minor injuries.
Aguinaga said investigators believe the crash was alcohol- and weather-related, but haven't arrested the driver yet because he is still in the hospital.
Police are not sure if anybody in the SUV was wearing a seat belt.