Pernell Whitaker, a longtime pound-for-pound king and one of the greatest boxers in history, was killed Sunday night when he was hit by a car in Virginia Beach, Virginia. He was 55.

The Virginia Beach Police Department said that the incident remains an active investigation but that Whitaker was apparently hit by a vehicle at around 10 p.m. Sunday when he was walking at an intersection.

"When officers arrived on scene they located an adult male victim who had been hit by a vehicle. The victim succumbed to his injuries on the scene," Virginia Beach Police Department spokesman L.M. Bauder said in a statement. "The driver of the vehicle remained on scene with police."

Whitaker, a southpaw from Norfolk, Virginia, was revered as perhaps the best defensive fighter in history as his slick moves confounded opponent after opponent.

Whitaker, who was inducted into the International Boxing Hall of Fame in 2006, won world titles in four weight classes. He was the undisputed lightweight world champion and also won titles at junior welterweight, welterweight and junior middleweight as the one of the dominant forces in boxing for much of the 1980s and 1990s. He won a gold medal at the 1984 Olympics.

Whitaker's youngest son, Devon Whitaker, told the Virginian-Pilot newspaper that his dad was a "cool guy."

"That all I can say about him," he told the newspaper. "I can't really say how I'm feeling because I'm feeling shocked. I'm still trying to process everything that's going on. But he was a cool guy."

"I loved PW and he loved me -- there was no doubt," Main Events promoter Kathy Duva, whose company promoted Whitaker throughout his career and who remained close to him after his retirement, told ESPN. "He was this person who was only comfortable in the ring. He had demons, but when he was in the ring, that was when he was in control and when he was happy and when he was the very best at what he did, and he wanted to show that to everybody."