Veteran entertainer Donald O'Connor, whose show-stopping "Make 'Em Laugh" production number in 1952's Singin' in the Rain deftly combined comedy and acrobatics, died Saturday of heart failure. He was 78. O'Connor was also known for starring in the wildly popular Francis the Talking Mule comedies of the 1950s. According to his family, among O'Connor's last words were: "I'd like to thank the Academy for my lifetime achievement award that I will eventually get."