The crash happened around 4:15 a.m. on the lower deck of the Bay Bridge just before Treasure Island.
CHP says the three victims were occupants of a MINI Cooper that was hit by a pickup truck.
CHP says two people were pronounced dead on the scene. A third person in the MINI was transferred to a local hospital but was pronounced dead Thursday afternoon. The driver of the pickup truck was also taken to the hospital, and their condition is unknown.
CHP says the MINI stopped on the bridge before the truck hit the car from behind.
Three eastbound lanes of the bridge were closed for several hours as emergency crews responded, but they have since reopened.
Stay with ABC7 News for updates on this developing story.