Police say just after 1 a.m., a man began arguing with family members.
They say he got into his car and sped down State Street. He lost control of the vehicle on the State Street Bridge and went off the side and into the Cooper River.
Two family members jumped in to help him but were pulled out of the river by firefighters.
Rescue crews on the scene pulled the car out of the water with a body inside early this morning.
