Russell Johnson, Professor On 'Gilligan's Island,' Dead At 89

Russell Johnson, who played the professor on "Gilligan's Island," died Thursday morning, his agent told TheWrap. He was 89.

Johnson, the last surviving male castmember of the CBS sitcom, died at his home in Washington state of natural causes, his agent confirmed.

Johnson earned a Purple Heart as an aviation cadet in the Air Force during World War II before rising to fame on "Gilligan's island," which ran from 1964 to 1967.

The actor went on to guest-star on a slew of TV shows, but his last on-screen credit was in 1997.

Johnson published his memoirs, "Here on Gilligan's Isle," which offers fans behind-the-scenes anecdotes and answers the oft-asked question: how was the professor able to build a nuclear reactor and a car but never a boat?

Dawn Wells and Tina Louise (Mary Ann and Ginger) are the last surviving "Gilligan's Island" castmembers.

"My 2 favorite people are now gone. The Professor past away this morning. My heart is broken," Wells wrote on Facebook, referring to Johnson and star Bob Denver, who died in 2005.

She added, "Russell was a true gentleman, a good father, a great friend, and 'the rest.' I love him and shall miss him. My heart goes out to [his wife] Connie and his daughter Kim. I love you."