Stay calm. Take deep breaths and check if you are okay first. You can't do anything if you are in a panic.
An accident can start a lot of arguments. Accept fault if it is truly yours, else think of a solution to move on. Once you understand what has happened, you'll have a clearer process thought.
Instead of shouting expletives and going on a rage, be mindful that your actions or words have consequences. Check to see if the other party is alright as well.
Feel like you need to punch and kick something / someone? Check this video out. It is the perfect way to blow off steam if you really have to.
The heat of the moment doesn't warrant anyone hurting another. It is an accident after all. It wasn't intentional.
If you respond with rage, you might be met with some in return. Don't antagonize people. You might get hurt.
Everyone has a smartphone in hand these days and if you are in a heated situation, someone somewhere might be recording. Be mindful of this too.
Negotiate how you would like to settle, if no one is hurt. If you can't reach an agreement, report the incident to the authorities. It doesn't solve anything but it does help you move on.
Something worse could have happened to you. Be thankful you're not in that situation.