Former professional football player Merlin Olsen, who had a successful second career in broadcast TV, died Thursday in Duarte, Calif., of cancer. He was 69.

Olsen played his entire 15-year NFL career for the Los Angeles Rams from 1962-76. He then segued to NBC as an NFL color commentator and TV pitchman before landing dramatic roles, including the Peacock’s long-running “Little House on the Prairie,” and the lead in “Father Murphy.”

Born in Ogden, Utah, in 1940, Olsen played football in college and then had a successful pro career as a defensive lineman on Rams teams that featured him as a member of the “Fearsome Foursome” alongside Deacon Jones, Lamar Lundy and Roosevelt Grier, and landed him in the Pro Football Hall of Fame. Upon retirement in 1977, he joined Dick Enberg in the NBC broadcast booth as a commentator for the network’s NFL telecasts, as well as the Rose Bowl. He also was a spokesman for the florist FTD.

In 1977 he joined “Little House on the Prairie,” playing Jonathan Garvey until 1981, and then starred in the title role on the Peacock’s “Father Murphy.” Two more skeins followed, including “Fathers and Sons” and “Aaron’s Way,” which ended in 1988.

In a Twitter message, his “Little House” co-star Melissa Gilbert wrote, “He was one of the sweetest, kindest, men I have ever known. The personification of the Gentle Giant. Forever now, a guardian angel.”

Survivors include his wife, Susan; three children; three brothers; five sisters; and several grandchildren.