What is the impact on the community after a car crash?

This would depend on the location and severity of the accident. An accident occurring in a high traffic area with a fatality, could cause not only large traffic congestions, but members of said community to grieve the loss of a fatality.

A minor fender bender on a backroad would likely occur with little to no impact on anyone but those involved.

An accident occurring where hazardous chemicals are spilled could cause a disruption in said community as well. Chemcials like fuel may cause fires and drain into storm drains and pollute water tables.

So, in conclusion, it would really depend on the severity and location of the accident.