What options do I have?

[Bobby B]

My wife and I moved from Warren, Mi to Houston, TX about 1 year ago due to graduating from college and needing to find a job. We still own a house in Warren that is severely underwater (Currently owe $115k, likely worth around $45k) that we are renting to some people because we were unable to sell it for what we owe when we moved. The people renting the house really want to buy it, but we cannot possibly afford to pay the difference between what we owe and what it could sell for. The problem is, while we couldn't afford to pay the difference between owed and what it is worth, we can reasonably afford the mortgage in addition to our current mortgage in Texas. Would short sale be an option even though we likely could not show reasonable economic hardship? What other options do we have from a legal standpoint?

I could REALLY use some help on this. The renters are looking to buy something and stop renting. So either we sell them our house, or they vacate and find somewhere else.

THANKS in advance for any advice!