Do both sides flash at the same speed? If not, then one of the bulbs may be burnt out, Possibly from the accident.
I know when my car got crunched in the front, part of the wiring harness got pinched between two parts and got cut. The shop that did the work said they cut and spliced the wires, but for some reason when I've been driving a lot when it's hot out, the right turn indicator inside the car lights up dimly and the right turn signal stops flashing.
I haven't had a chance to poke around when it stops working. It usually starts working again before I stop the car.
Anyway, check all the lights, especially ones near the point of impact, and check the wires around that area.
Little, Yellow, Different New sig pic with 17's coming soon!