The California Highway Patrol says the crash happened around 1:45 pm near Floral and Cedar Avenues.
A flatbed truck was driving southbound on Cedar Avenue, while an SUV was traveling westbound on Floral Avenue.
The driver of the SUV didn't stop at a stop sign and collided with the flatbed truck.
Both vehicles caught fire.
The three people in the S-U-V could not get out and died at the scene.
The driver of the flatbed truck was taken to the hospital with major injuries but is expected to survive.
Officials are reminding drivers to pay attention on the road.
Roads were blocked for several hours in the area.
The three people who died have not yet been identified.