The crash happened at Avenue 18 1/2 and Road 16 just before 5:30 a.m.
The California Highway Patrol says 21-year-old Omar Hernandez of Planada was driving the car that ran the stop sign.
Two of his passengers were killed. Hernandez received major injuries and was taken to Community Regional Medical Center.
Three people in the other car were also taken to a hospital. Investigators do not think alcohol is to blame for the crash.
