“Some other negative situation” covers just about everything.
My family was overrun in medical debt (despite having insurance) and we considered a short sale just to get out so we didn't foreclose. We figured it would be better in the long run to walk away with good credit and a chance to own again in the future than to have the black mark of a foreclosure on our record.
Thankfully, we were able to hang on. Took us years to pay off that debt, but we did - to the last penny, and kept our house and exceptional credit rating intact.
Sacrifice, sacrifice, sacrifice...worth it in the end.