There were five vehicles involved in the collision which was reported at 5:04 p.m., according to the California Highway Patrol.
Officers say a pickup truck was traveling east just outside of Davis when it came to stopped traffic. For some reason, the driver didn't see that traffic had stopped and slammed into the back of a car causing a chain reaction crash, according to investigators.
The driver of the pickup suffered some broken bones but his passenger received critical injuries and was airlifted to UC Davis Medical Center. The 48-year-old man, from Pomona in Southern California, later died from his injuries.
No one involved in the chain reaction was seriously injured.
Officers say it does not appear that alcohol or drugs was involved.
The four eastbound lanes were closed for about an hour, tying up commute traffic.
All lanes were reopened around 6:30 p.m.