These pictures show some of the damage raccoons can due to a attic.
In the insulation on the first picture you can see were the raccoons really worked it over. The next two pictures shows scat the raccoon left in just a short time. Notice the piles of bird droppings as well.
The chimney gave these critters direct access to the attic and made a nice roosting site for the pigeons and a home to five raccoons.