Authorities have not confirmed the identities of the victims, but a sibling has identified the adults as Jalson and Arlene Laguta and a friend from their church and the two children as Caleb and Joseph Laguta.
The Kern County Sheriff's Office has identified the fifth passenger as 60-year-old Danilo Aquino.
Reports of the crash came in just after 5 p.m. Officials reported a vehicle crashed into a tree near Cecil Avenue.
Witnesses tell CHP the vehicle had been moving erratically on the highway.
The cause of the crash is unknown, and an investigation is underway.
This is a developing story and will be updated.