Hansel J. Cato, 77, West Donegan Avenue, Kissimmee, died Monday, June 9  of a heart attack. Mr. Cato was a schoolteacher. Born in Nashville, Ga., he moved to Central Florida in 1920. He was a member of Veterans of Foreign Wars. Mr. Cato was a World War II Marine veteran. Survivors: brother, Julian R., Orlando; 15 nieces and nephews.