ATWATER, Calif. - Experts from the National Transportation Safety Board are investigating a bus crash that killed four people and injured 23 on a central California highway.
Senior highway accident investigator Don Karol said Wednesday that it's not known what occurred immediately before Tuesday's crash and that the NTSB will be working with the California Highway Patrol to find out.
The driver survived, but officials haven't been able to speak to him because of his injuries.
Authorities say there were 27 people on the bus, including the driver. Besides the passengers who died, seven suffered major injuries, three had moderate injuries and 13 received minor injuries.
California Highway Patrol says the charter bus was driving north on Highway 99 near Livingston in Merced County from Mexico to Pasco, Washington, when it swerved for some reason and hit a sign pole early Wednesday.
According to California Highway Patrol Officer Moises Onsurez, the sign pole sheared through the center of the vehicle.
The bus started its journey in Mexico, stopped in Los Angeles on Monday night and was on its way to the Sacramento area en route to Pasco Tuesday.
