SALT LAKE CITY (AP) -Hall of Famer Merlin Olsen, who helped form one of the NFL's greatest defensive lines before embarking on a successful career in television, died Thursday after a battle with cancer. He was 69.

Olsen was a member of the Los Angeles Rams' ``Fearsome Foursome'' along with Deacon Jones, Lamar Lundy and Rosey Grier in the 1960s. He later starred on NFL broadcasts, commercials, and as Jonathan Garvey on the TV series ``Little House on the Prairie.''

``He was ferocious and fearless on the football field and then the other probably more important aspect of his personality was he was a true gentleman,'' said fellow Hall of Famer Jack Youngblood, his teammate with the Rams in Los Angeles. ``We all know what a wonderful, tremendous football player he was, but he was so much more than that.''

Utah State, Olsen's alma mater, said he died outside of Los Angeles. He was diagnosed last year with mesothelioma, a cancer of the lung lining often linked to asbestos.

Olsen filed a lawsuit last year, claiming he contracted the disease as a result of being exposed to asbestos on construction sites where he worked as a child and young adult.

``He cared deeply about people, especially those that shared the game of football with him,'' NFL commissioner Roger Goodell said. ``Merlin was a larger-than-life person, literally and figuratively, and leaves an enormously positive legacy.''

Olsen was a consensus All-American at Utah State and won the 1961 Outland Trophy as the nation's best interior lineman. The Rams drafted him third overall in 1962 and he spent the next 15 years with the team, and is still the franchise's career leader in tackles with 915. He was picked to 14 straight Pro Bowls, a string that began with his rookie year.

He joined Deacon Jones, Lamar Lundy and Rosey Grier on the Rams' storied ``Fearsome Foursome'' defensive line known for either stopping or knocking backward whatever offenses it faced. The Rams set an NFL record for the fewest yards allowed during a 14-game season in 1968.

Youngblood joined the Rams as a rookie in 1971, backing up Jones as Olsen continued to anchor the other side of the line. Youngblood remembered Olsen telling him as a young player to push to be great not just on every play, but with ``every heartbeat.''

``When you stop and think of Merlin on the field, he accomplished things that will never be accomplished again,'' Youngblood said. ``If it hadn't been for Merlin Olsen, I wouldn't have turned out to be the football player that he helped mold and make.''

Former Green Bay Packers offensive lineman Jerry Kramer remembered dreading Olsen, in his 1968 book ``Instant Replay,'' co-written with late sportswriter and broadcaster Dick Schaap.

``I'll be facing Merlin Olsen, and that's definitely work, not fun,'' Kramer wrote. ``Merlin never lets up. He'll run right over you no matter what the score is.''

Olsen was voted NFC defensive lineman of the year in 1973 and the NFL MVP in 1974, and was voted to the Pro Football Hall of Fame in 1982.

``Merlin Olsen is one of the best players in the history of the NFL,'' Rams general manager Billy Devaney said. ``His passing is a tremendous loss for the Rams. He will always be remembered as an ambassador for the organization as well as the National Football League.''

Olsen made a few television cameos during his football career and turned to acting full time after he retired in 1976. He's best remembered for his role alongside Michael Landon and Melissa Gilbert on ``Little House on the Prairie'' from 1977-81, and on the short-lived ``Father Murphy.''

He also stayed in the game as a broadcaster. Olsen wasn't just some former player who knew football and would weave tales of his playing days into the broadcast. The son of a former school teacher, Olsen graduated summa cum laude at Utah State with a degree in economics and earned a master's in economics in between his 15 NFL seasons.

``Merlin was a valued and cherished member of the NBC family in the 1970s and '80s. He loomed as large in the broadcast booth as on the football field,'' NBC Sports president Ken Schanzer said. ``Merlin brought both his knowledge of the game and his humanity to bear on his work.''

Utah State honored Olsen in December by naming the football field at Romney Stadium after him. Because of his illness, Olsen's alma mater didn't want to wait until football season and made the announcement during halftime of a basketball game.

Olsen was well enough to attend, but did not speak at the event. He stood and smiled as he waved to fans during a standing ovation and chants of ``Merlin Olsen!'' and ``Aggie Legend!''

Utah State is also planning a statue of Olsen at the southeast corner of the stadium.

``This was the voice of a man who not only became one of our country's most decorated athletes, but also one of the most accomplished and respected people ever to hail from the state of Utah,'' said Stan Albrecht, president of Utah State.

The Rams also honored Olsen during a game Dec. 20, with a video tribute narrated by Enberg. Olsen did not attend because of his health. His name was already part of the Ring of Fame inside the Edward Jones Dome in St. Louis along with other franchise standouts.

``I love the game of football,'' Olsen said in his Hall of Fame induction speech. ``There was some special magic out on that piece of grass out there on that field. And win or lose when I came off that field, it was always coming down. I am sure that the thing I miss most about the game is the people, the very special people and those incredible highs and lows.''

Olsen is survived by his wife, Susan, and three children. There was no word Thursday on funeral arrangements.