First, get to safety and check everyone for injuries. Call 911 to get a formal...

https://iris-wiki.win/index.php/How_to_Keep_Track_of_Insurance_Calls_After_a_Crash_(And_Why_Your_Memory_Isn%E2%80%99t_Enough)

First, get to safety and check everyone for injuries. Call 911 to get a formal police report on file. While waiting, take clear photos of the damage and grab contact info from any witnesses. Keep your comments brief