Why do I need title search before buying from mortgage auction?

[Jennifer T.]

I've read that title search is a must before buying a property from a mortgage auction. I've also read that existing liens and any second mortgage are wiped following the first mortgage foreclosure, so why do I still have to conduct title search? 

I assume that the first mortgagee made sure title was good (since title insurance was a requirement) before granting the loan. So, what's there to look for? If it matters, this is for Pennsylvania.

Your insight is much appreciated, thanks!