sub to financing

I am looking at doing a deal with someone and their personal financials are in terrible shape. Great deal since I can get a bargain on their house, however my question for all you " sub to" pros out there is this: If I am able to work out a sub to deal with them what happens if their personal situation gets worse and they file for bankruptcy ?

Would that be of any concern to me? Could I lose the house down the road if they did file? Or since they would deed it over to me then its not an issue? I have a feeling it would create a due on sale clause of some sort if they did file?

Any and all opinions and expertise is much appreciated!