ATWATER, Calif. (KFSN) --Investigators are trying to find answers to what caused a charter bus to crash into a highway road sign near Livingston.
It was a horrific scene when four were killed after a bus swerves off the road and is split in two. The California Highway Patrol said the accident happened around 3 a.m. on Tuesday.
Witnesses claim to have seen the bus swerving to avoid hitting another car, and said the heard the bus making strange noises.
"I thought the bus ran over something because it sounded like it was clicking like, 'click-click-click' on the road. And when I lowered my window it got louder," said Jose Bustamante, Atwater Resident, Saw Bus Crash.
"As far as vehicle movement trajectory, all those components are being gathered. It's a lot of info to go through. It's going to take months for us to get to the bottom of everything," said Captain Brian Hawkins, CHP.
Five people were originally reported dead, but that number went down to four.
The National Transportation Safety Board will also have investigators looking into several areas, including the driver and his training as well as the bus company itself.
"We have no indication that this driver was fatigued-- we're not anywhere near that. But with fatigue we've made recommendations dealing with hours of service for drivers," said Don Karol, NTSB.
The CHP said the driver of the bus is in the hospital with serious injuries he sustained in the accident. Witnesses said the bus driver may have been with by another vehicle.
"I saw the bus driver, he was running around telling people what to do and then the next thing I hear-- I saw the car go by, it was like a Honda or Toyota-- because he almost hit me too and it almost hit other people but I think he (the bus driver) got hit," said Bustamante.
CHP said the investigators will be at the scene the remainder of the week trying to figure out exactly what caused the bus to crash.