The only case there will be no case of contract or your contract can be terminated is when the subject of the contract is related to the Employer.
But in the case of the Employee, the contract automatically ends when he/she dies or becomes disabled.
They will be need of medical certificate to prove whether or not there has been such an occurrence.
Note, if the employee becomes disabled but there is another work that you can do with your disability, your employer will have to give you that work and pay you the same amount he was paying you before, whether the task before was huge or not, and now you are doing smaller one. The same wages, bonuses, and compensation will be given to you when you assume your new role.