I was getting my oil changed yesterday, at the place I take it everytime.
They did the oil change, and i heard the guy underneath say something about a crankshaft seal.
they had a little discussion and the other guy went underneath to look. and then while the other guy was underneath. they told me to start it up.. so i started it, and they said the crankshaft seal sucked up into the engine ( it made a really high pitched noise when i started it ) then they told me what happened and that I should get it looked at by the dealership or someone else.
My question (i have minimal car knowlege) how big a deal is it to have that happen? is it something urgent?

and how would it happen, could it be something that they didnt do right, or will it happen in general wear and tear? any help is greatly appreciated