CHP officers say a Dodge caravan was heading west on Avenue 7 around 5 am Thursday when the driver tried to make a left turn onto Road 21.
A Volvo driving behind the caravan was trying to pass traffic, but didn't see the Dodge making the turn until it was too late.
Officers say the Volvo then slammed into the side of the caravan, causing it to overturn, killing the 54-year-old driver inside.
A woman passenger also in the van suffered major injuries and was air-lifted to the hospital.
The driver of the Volvo accused of causing the collision is also in the hospital with major injuries.
The victim killed in the crash has not yet been identified.