Gun discharged inside car right behind me

[pitor]

Happened 10 minutes ago. As I'm driving to the airport to pick up my wife, I'm stopped at a red light. I look up to my rearview mirror and I see a flash of light and hear a loud bang. The dogs are with me and they jump from the pop. A gun was absolutely discharged. I'm not sure if it was discharged at the car next to the car behind me, or just an accident. As soon as we get the green light the car behind me veers to the right and onto a side street. Could not call the cops because I could not see the make and model of the car behind me. Nor did I care I just wanted to put distance between me and the cars behind me. Very bizarre the whole thing.