Olsen had been diagnosed with mesothelioma. In January he filed a lawsuit against NBC Studios, NBC Universal and 20th Century Fox for exposing him to absestos, according to TMZ. In that suit he also sued Sherwin Williams and Lennox Industries. Olsen claimed besides being exposed to absestos as an adult, he was also exposed when he was a child; thus the reason he included Sherwin Williams and Lennox in his suit.
Prior to starring as Father Murphy, Olsen had been a regular on "Little House on the Prairie" from 1977 to 1981.
Olsen played his entire 14-year professional football career for the Los Angeles Rams as a defensive tackle. He was part of the team’s "Fearsome Foursome," which also included Deacon Jones, Rosey Grier and Lamar Lundy. Lundy died in 2007. In 1999 the Sporting News listed the 100 Greatest Football Players of All Time, and Olsen ranked No. 25. He retired from football at the end of the 1976 season.
For much of the 1980s he was a color commentator for NBC football games.