What is "good cause" for breaking a contract? My contract states $2,500 fine unless there is good cause
Suddenly moving out of state because... your spouse's job transferred them or you have to be the main caretaker for an ill family member
I would think anything that causes you to move more than a reasonable commuting distance from school in order to keep your family together would be considered "good cause". They may ask you to stick around through a transition period, but it's likely that they'll release you.
It'll depend on the district. A few years ago at my old district, a coworker's husband got a job out of state and the board did not let the wife out of her contract. I thought that was totally ridiculous and unfair, but hopefully that is an exception to the rule. Holding a person hostage and forcing a family to live separately is not how you should treat fellow humans. Her position was not one of those where there's only five people in the whole state with that certification. I think we'd been able to find a December graduate.
Health reasons. Anxiety and post-traumatic stress disorder are common enough. Strange allergies: you have shortness of breath, wheezing, and dizziness every time you go to work. Clears up some time after you leave the building. No one is going to take you to court and argue they have a right to make you suffer. Relocation. You're moving out of state. But then your plans fell through. Oh, darn.