Retired Ann Arbor Police Detective Rich Kinsey recently wrote an article with steps to follow if you are first at the scene of a serious automobile accident. http://www.annarbor.com/news/first-on-the-scene-of-a-serious-crash/
Officer Rich Kinsey recommends the following:(1). Keep yourself safe and park your car well off the roadway with emergency flashes on (far enough that if there is an explosion your car won't be involved);(2). Stay in your car and gather yourself so that your judgment is not clouded by your natural Adrenaline rush;(3). Call 911 and be prepared to give location and description of the accident scene you can see;(4). Before getting out of your car look for secondary threats such as oncoming traffic, traffic from behind, and downed electrical wires. Check your mirrors before opening your car doors;(5). As you approach the crash look for things like fire or ruptured fuel tanks;(6). Look for injured victims and know your own first-aid capabilities and limitations;(7). Speak to injured victims in the calmest, lowest, slowest voice possible telling them to not move and that "help is on the way." Calm the victim by asking the victim questions like "is anyone else in the vehicle." Or ask them their name, age, and other general information about themselves that may be helpful to emergency personnel. (8). Be on the look-out for the walking wounded, drunks, and drugged people that may wander out into traffic. Get them to sit down and stay still until emergency responders arrive on the scene;(9). Call 911 back and update the dispatcher on what you have found at the scene;(10). When the police arrive give them your name and contact information and leave the scene when they tell you may leave;(11). Take care of yourself realizing that you may have trouble sleeping, eating or thinking about the incident. Talk to a crisis counselor if you continue to experience post-accident issues.