Mississippi Highway Patrol Troop D Sargent Ben Williams said the two-car accident was caused when one vehicle hydroplaned, lost control and collided with another oncoming vehicle.
Donovan Dukes, 43, of Cleveland, was heading north in a 2011 Dodge Avenger when the wet roads lead to his vehicle hydroplaning.
His car skidded into the southbound lane and was hit broadside on the passenger side by a 2002 Nissan Altima being driven by Ashley Hargett, 27, of Clarksdale.
Hargett's two young sons, Jordan, 2, and Jaylin, 4, did not survive the accident.
Jordan died at the scene and Jaylin later died at the Delta Regional Medical Center in Greenville.
Williams said both were properly restrained at the time of the accident.
Hargett was taken to the University Medical Center in Jackson where she is in stable condition.
Dukes died at the scene and was taken to the Sunflower County Coroner.
Williams said Dukes was not wearing a seatbelt and it hasn't been confirmed if speeding was the cause of the hydroplaning.