Dispatched at 0540 hrs for a vehicle accident...Units arrived on scene and found a vehicle had traveled off of the road in between the guard rails separating the north and south bound bridges... Vehicle then went into water and victims were trapped... One male victim stated that he broke the window with his arm and all four victims were able to escape... 3 victims were transported to the hospital with minor injuries and one refused transport...At approx. 14:30 hrs DelDot shut Northbound Coastal Hwy down for the tow truck and diverted one lane into the southbound hwy for a little over one hour... South bound traffic heading to the beaches was backed up for about a mile... Units On Scene: 85-4, Rescue 85, 85-11, A-85, Medic 104, 85 Fire Police, DSP,and Milton PD..