You need to consult a local estate attorney. In most states, when people own property together and then divorce, the divorce decree converts their ownership to a tenancy in common. That means that they each own half, and if either dies, that person;'s share passes to his or her estate. If the person left a will, the will would deternine who are the beneficiaries of the estate. If no will, state intestacy law controls, which names close relatives in order of priority, which does not include former spouses. So, odds are that you are a half owner and your ex's estate owns the other half. Normally that would be his children.
Please note that I do not practice in your state and the above is not intended as legal advice, is for educational purposes only.