FORT LAUDERDALE, Fla. -- Leslie Nielsen, a Canadian-born actor who went from drama to inspired bumbling as a hapless doctor in "Airplane!" and the accident-prone detective Frank Drebin in the "The Naked Gun" comedies, died on Sunday in Florida. He was 84.

His agent, John S. Kelly, said Nielsen died at a hospital near his home in Ft. Lauderdale where he was being treated for pneumonia.

Nielsen's nephew Doug Nielsen, who lives in Richmond, B.C., said his uncle had been hospitalized for the past 12 days and died in his sleep with wife Barbaree by his side.

Nielsen's Canadian roots run deep. Though he eventually became a naturalized U.S. citizen, his father was a Mountie and his brother, Erik Nielsen, served as an MP in Yukon and as deputy prime minister in Brian Mulroney's Conservative government.

Leslie Nielsen was born Feb. 11, 1926 in Regina.

At age 17, he enlisted in the Royal Canadian Air Force and trained as an aerial gunner.

After the war, he worked as a disc jockey at a Calgary radio station, then studied at a Toronto radio school operated by Lorne Greene, who would go on to star on the hit TV series "Bonanza." A scholarship to the Neighbourhood Playhouse brought him to New York, where he immersed himself in live television.

Nielsen appeared in more than 100 films, including 2002's "Men With Brooms," co-starring Paul Gross. In recent years, he appeared on the Canadian TV series "Robson Arms."

Among his lesser known, but truly-Canuck performances, was a two-minute narration for a video shown to the Queen and thousands of spectators in England when she was presented with a horse from the RCMP's Musical Ride in 2009.

In 2003, Canadian actors union ACTRA presented him with its Award of Excellence for more than a half-century of making movies.

Nielsen came to Hollywood in the mid-1950s after performing in 150 live television dramas in New York. With a craggily handsome face, blond hair and 6-foot-2 height, he seemed ideal for a movie leading man.

Nielsen first performed as the king of France in the Paramount operetta "The Vagabond King" with Kathryn Grayson.

The film -- he called it "The Vagabond Turkey" -- flopped, but MGM signed him to a seven-year contract.

His first film for that studio was auspicious -- as the space ship commander in the science fiction classic "Forbidden Planet." He found his best dramatic role as the captain of an overturned ocean liner in the 1972 disaster movie, "The Poseidon Adventure."

He became known as a serious actor, although behind the camera he was a prankster. That was an aspect of his personality never exploited, however, until "Airplane!" was released in 1980 and became a huge hit.

Between films he often turned serious, touring with his one-man show on the life of the great defence lawyer, Clarence Darrow.

Nielsen has stars on both Hollywood's and Canada's Walk of Fame.

He was named an Officer of the Order of Canada in 2002.

Nielsen also was married to: Monica Boyer, 1950-1955; Sandy Ullman, 1958-74; and Brooks Oliver, 1981-85.

Nielsen and his second wife had two daughters, Thea and Maura.

- With files from The Associated Press, Tamsyn Burgmann