It happened about 2:20 a.m. Wednesday on Hastings Farm Road in Seaford. Troopers say 23-year-old James Serge of Seaford was driving south when he saw two deer standing in his path.
Police say Serge braked and swerved, causing the vehicle to leave the wet road, hit a driveway pillar and a brick abutment.
Officers say Serge was ejected from the car, which continued down an embankment and hit a tree.
A passenger in Serge's car, 28-year-old Gamson Milce, was pronounced dead at the scene. Officers say Serge is in stable condition at a local hospital.