1993 Dodge Intrepid Loss of all Power While Driving

First of all the car may have run out of gas while son was taking a classmate to school. While appraoching a curve in the road the engine shut off and the car lost all power causing the steering to stiffen and become unmanageable and the car jumped a ditch causing sever damage. Boys are OK fortunately but the car and undercarriage may be totalled. Now when attempting to start everything is dead. No signs of weak battery and the car should still turn over with or without gas. What would cause the car to just lose all power "while driving"? Thx