The cause of death for Mary Tyler Moore was revealed on Monday. According to TMZ, the actress and activist died of cardiopulmonary arrest, brought on by other serious contributing health issues. Moore, 80, was said to be suffering from aspiration pneumonia, hypoxia (lack of oxygen to her tissues) and diabetes mellitus as well, reports TMZ. The Emmy-winning actress was best known for her TV sitcom roles in "The Mary Tyler Moore Show" and "The Dick Van Dyke Show.” Moore was laid to rest in Connecticut on Monday during a private ceremony.