San Marino, Calif. ? Hall of Fame jockey Bill Shoemaker, who rode four Kentucky Derby winners and was a commanding presence in thoroughbred racing for more than 40 years, died Sunday. He was 72.

Shoemaker died in his sleep at his suburban home near Santa Anita racetrack, according to longtime friend and trainer Paddy Gallagher. Gallagher, an assistant during Shoemaker’s training career, said doctors told him Shoemaker died of natural causes.

He had been paralyzed from the neck down since a car accident in 1991.

It was the second major death in horse racing this year. Johnny Longden, who won the Triple Crown aboard Count Fleet in 1943 and was the only jockey to ride and train a Kentucky Derby winner, died in February at 96.

Shoemaker broke Longden’s record of 6,032 career victories in 1970 and held it until Laffit Pincay Jr. broke Shoemaker’s mark of 8,833 wins in 1999.

“He was one of the greatest human beings I have ever had the pleasure of knowing in my life,” said retired jockey Chris McCarron, now general manager of Santa Anita. “Forget about his ability to communicate with horses, his compassion for people was second to none.”

Only 4-foot-11, the athlete known simply as “The Shoe” rode for 41 years, most of them in Southern California, considered to be the most competitive circuit in America.

“For a man his size, wearing a size 21/2 shoe, he was a giant,” retired Hall of Fame jockey Eddie Delahoussaye said.

Shoemaker broke his neck when he veered off the highway in his Ford Bronco in suburban Los Angeles, tumbled down an embankment and rolled.

He had been drinking after playing golf, and police said his blood-alcohol level was twice the legal limit.

He sued Ford and won a multimillion-dollar settlement.

He continued training horses for another six years despite being in a wheelchair.

He operated the chair by turning his head and breathing into a tube.

“I knew the last couple of years he was having problems,” said Delahoussaye, who last spoke with Shoemaker four days ago. “Shoe never let on. He was a quiet guy, he kept a lot of things to himself. He never complained.”

Pincay, who was forced to retire after breaking his neck in March, called Shoemaker last week and told him about a trip Pincay had taken to New York to help find a cure for paralysis.

“I told him how close they were to finding a cure, and he was very excited and sounded happy about it,” Pincay said Sunday. “I know he wasn’t happy in that wheelchair, but he never complained.”

In 1986, at age 54, he became the oldest jockey to win a Kentucky Derby when he guided Ferdinand along a small opening on the rail in a ride considered one of the greatest ever.

That win came 21 years after his previous Derby win, aboard Lucky Debonair in 1965.