The crash, which happened at about 12:10 p.m. on Saturday in the 18800 block of State Highway 99, involved four people including the 18-wheeler driver, pickup driver and his passenger, and a forklift driver.
Authorities said the 18-wheeler hit the rear of a Ford F-350, which then struck the back of a forklift.
The sheriff's office said the forklift driver and passenger of the Ford F-350 were taken to a local hospital and sustained minor injuries.
Deputies say the driver of the Ford F-350 succumbed to his injuries from the crash.
According to officials, the driver of the 18-wheeler admitted that he had been reading texts on his phone shortly before the collision.