Bill Fitch, who guided the Boston Celtics to one of their championships during a Hall of Fame coaching career spanning three decades, has died. He was 89.

A two-time NBA coach of the year, Fitch died Wednesday in Lake Conroe, Texas. Fitch’s daughter, Marcy Ann Coville, told Indiana Pacers coach Rick Carlisle her father was surrounded by family. The cause of death was not immediately known.

Fitch coached for 25 seasons in the NBA, starting with the expansion Cleveland Cavaliers in 1970. He was Larry Bird's first pro coach with Boston in 1979, won a title with the Celtics in 1981 and spent time with Houston, New Jersey and the Los Angeles Clippers.

While he had his greatest success in Boston, Fitch may be best remembered for his early seasons with the Cavs.

He helped develop a young team that won just 15 games in its first season before making the playoffs in 1976 and shocking the Washington Bullets in what became known as the “Miracle of Richfield.”

Fitch was chosen coach of the year that season.

“Coach Fitch earned the love and respect of his Cavaliers players as he embedded a high standard of accountability and a belief system that he felt was a reflection of the team’s motto as a ‘group of daring, fearless men, whose life’s pact was never surrender, no matter what the odds,’ something that continues to be greatly valued by those he coached and worked with on and off the court,” the Cavs said in a statement.

“Coach Fitch was a great friend and trusted mentor and teacher to so many across the entire basketball community, while his impact on the game, and the lives of those he touched, spanned multiple generations. He became a life-long friend to many members of the Cavaliers organization.”

Fitch was hired by the Celtics in 1979, the same year Bird arrived in Boston. The Celtics went 61-21 in Fitch's first season and won the championship the following year by beating the Rockets in six games.

He spent five seasons (1983-88) in Houston and went to the Finals in 1986 with a team powered by Hakeem Olajuwon and Ralph Sampson.

Fitch, who retired in 1998 with a coaching record of 944-1106, was elected to the National Basketball Hall of Fame in 2019.