A method and a system of controlling a restraint device in a vehicle during a crash. The method includes sensing a lateral acceleration without using other vehicle dynamic information. The method also includes integrating the sensed lateral acceleration to determine a change in (or delta of) lateral velocity, low-pass filtering the sensed lateral acceleration, and extrapolating the delta lateral velocity and the filtered acceleration to estimate a vehicle lateral velocity. The method also includes sensing a vertical acceleration, integrating the sensed vertical acceleration, combining the integrated vertical acceleration and the predicted vehicle lateral velocity to give an indication of how severely the vehicle laterally hits an obstacle, and generating a deployment signal to activate the restraint device.