Volunteers, your neighbors, your community, that's what people have traditionally relied upon. Professional responders do not come into being until cities need them, in part because the areas stop being the type of communities that allow neighbors to rely on each other.
I can think of an occassion when a bunch of volunteers poured out of their homes, assembled, and defeated what they thought was a hostile action undertaken by the most powerful army in the world, on April 19, 1775.