Former television producer and executive Grant Tinker, who was behind some of the most popular and critically acclaimed shows in U.S. television history, has died at age 90. Tinker, who died Monday at his Los Angeles home, began his career in advertising in the early 1950s and soon worked in executive jobs at NBC and Hollywood studios, developing shows for television. He and his then-wife, actress Mary Tyler Moore, formed their own production company in 1970, creating such hits as The Mary Tyler Moore Show, The Bob Newhart Show, Hill Street Blues, St. Elsewhere and WKRP in Cincinnati. These series became known for their ensembles of fine dramatic and comedic talent and quality writing. They appealed not only to critics but also to a more literate and sophisticated TV audience that rejected juvenile comedies and violent police melodramas. Tinker took over troubled NBC television in the early 1980s and helped raise it from the least popular to the top-rated U.S. network. Moore credited his success to what she called his unique understanding that "the secret to great TV content was freedom for its creators and performing artists."