Katherine Helmond arrives for the premiere of the Disney/Pixar animated film &#8220;Cars&#8221; in 2006 at Lowe&#8217;s Motor Speedway in Concord, N.C. Helmond, best known as the grandmother who was hot for housekeeper Tony Danza on &#8220;Who&#8217;s The Boss,&#8221; died Feb. 23 of complications from Alzheimer&#8217;s disease at her home in Los Angeles, her talent agency APA announced Friday. She was 89. 