Firstly, do not drive away. Ensure to get the details of anyone who was involved or saw the accident happen, even if you don’t think you’ll need them. For the protection of others, put your hazards on to show your cars aren’t moving and to prevent worse damage happening. Then call the police as you may need a report form from them to claim insurance and make sure your story is true and accurate. Most importantly, stay calm and seek medical help if you or anyone else needs it.