This excerpt taken from the MRO DEF 14A filed Mar 13, 2007.
Death or Disability
In the event of death or disability, officers will be entitled to the vested benefits they have accrued under Marathons standard benefits programs. Long-term incentive awards will immediately vest in full upon the death of an officer, with performance shares and performance units vesting at the target level. In the event of disability, long-term incentive awards will continue to vest as if the officer remains employed during the period of disability.