Don't know about the US much, but I can give some advice from the UK. I personally don't do this but one of my really close friends does this, he actually has a friend that works in a mortgage repossession side of a bank and gets tip off's of people that are about to go under and he goes in and basically buys the houses for next to nothing, but he has loads of investors so he never actually pays just swaps contracts! but he does have money to settle if he has to.
It's hard but very good money, if you can get a good team together then work together and all of you does one part, for example:
You: Finds investors/buyers
Partner 1: Works in a Bank
Partner 2: is their only if you have to settle (don't know the laws in the US but here in the UK once the timeline has ended you have to settle or lose your deposit.)
Good luck, if I can help anymore please PM me.
I'm actually in construction myself, not in the UK but Iraq.