If you are the first person to come upon the scene of a collision, the first thing you should do is stop and pull your vehicle off the road. Do not move injured persons unless there is a danger of fire or explosion. Notify emergency officials and do not stand in traffic lanes. Ask passing drivers, bikers, or pedestrians to assist you and warn approaching traffic, if needed. If you've been trained in first aid, help the injured. If someone is bleeding, apply pressure to the wound to stop it.