First, get to safety. Check yourself and others for injuries, then call 911 to...

https://dlf-ne.org/what-if-the-other-driver-changes-their-story-later-a-paralegals-guide-to-protecting-your-claim/

First, get to safety. Check yourself and others for injuries, then call 911 to get an official police report. Take photos of the scene and collect contact info from witnesses