The accident happened in the Cypress area on Highway 249 near Grant Road around noon. Deputies say a Honda Civic left the feeder road and struck a stopped Honda Odyssey minivan, flipping both vehicles in a violent crash.
Authorities at the scene originally said both drivers died, but deputies have now corrected that information. The victims who died at the scene were passengers, one of whom was a 19-year-old woman.
Two adults and a child were taken to area hospitals, some by Life Flight.
Two adults are listed in critical condition. An 18-month-old baby is expected to survive. No other information on the victims was immediately available.
Investigators believe speed was involved but not alcohol.