James MacArthur, best known for playing Detective Dan Williams in the original Hawaii Five-O TV show, has died of natural causes at the age of 72.
The actor passed away in Florida with his family by his side, his agent Richard Lewis said.
For 11 years MacArthur appeared in Hawaii Five-O, one of the longest-running crime shows in US TV history.
Son of playwright Charles MacArthur and actress Helen Hayes, MacArthur also appeared in several films.
They include Swiss Family Robinson and the western Hang 'Em High, alongside Clint Eastwood.
MacArthur's appearance in 1958 film The Young Stranger earned him a BAFTA for most promising newcomer.
He made his Broadway debut opposite Jane Fonda in Invitation to a March, going on to win the Theatre World Award for best new actor in 1961.
Yet it is for his role in Hawaii Five-O, which the actor spent 11 years playing, that he remains best known.
Episodes often ended with detective Steve McGarrett - played by Jack Lord - saying the show's catchphrase: "Book 'em, Danno!"
MacArthur quit the role before the programme's final season, saying he had grown bored with the show.
"The stories became more bland and predictable and presented less and less challenge to me as an actor," he said.
He is survived by Helen Beth, his wife of more than 25 years.
Ok...1, 2, 3...BOOK 'EM DANNO!