Squirrels are a menace. I'll have to name one of my fighting ships after one.
I always use "gets run over by a squirrel" instead of of "gets hit by a bus" when discussing business continuity plans.
"Look, I know Sam is a great worker, but what happens tomorrow if she goes out for a walk and gets run over by a Squirrel? She's the only one that knows those processes and we need those processes for business to continue. Therefore, we need to crosstrain Sam and Fred so that if either of them become unavailable, we don't lose either of their skill sets."
Being run over by a squirrel just makes something horrible sound a little less macabre.