[BC] Tent caterpillar ( ? ) infestation

[donroden at hiwaay.net]

Went to an FM on a mountain yesterday and there were little  
caterpillar-like worms crawling all over the outside walls ... fuzzy   
with multiple legs.

Inside were thousands on the painted concrete floor all dried-up and dead.

Thankfully, I had a broom and was able to sweep a path clear to the  
equipment rack and then sweep all of them back out the front door.

This is the first time I have seen this problem at this site.

Where / Why did they come and why were they all dead on the floor and  
alive on the outside wall ?

I called the pest control people but they won't be available until Monday.

Don R