Gregg Popovich shared a "deep sense of loss" and Doc Rivers battled tears as two of the NBA's most recognisable coaches addressed Kobe Bryant's death.

Los Angeles Lakers legend Bryant, 41, and his 13-year-old daughter Gianna died in a helicopter crash in Calabasas, California on Sunday.

NBA commissioner Adam Silver confirmed their deaths after the news was initially reported by American outlet TMZ.

Nine people were believed to have been killed in the incident, the Los Angeles County Sheriff's Department announced. There were no survivors.

The San Antonio Spurs were among the first teams to take to the court after the news emerged and head coach Popovich said their sorrow would stretch far and wide.

"Everybody's pretty emotional about the tragedy with Kobe," Popovich told reporters after a 110-106 loss to the Toronto Raptors.

"All of us know what a great player he was, but he went beyond great playing. He was a competitor that goes unmatched. It's what made him as a player so attractive to everybody, that focus, that competitiveness, that will to win.

"Even more importantly than that, we all feel a deep sense of loss for what he meant to all of us, in so many ways. So many millions of people loved him for so many different reasons. It's just a tragic thing.

"We all think about the family and the process they're going to be going through right now. That's where our thoughts should be."

Los Angeles Clippers coach Rivers retired from playing the season before Bryant debuted and struggled through an emotional news conference prior to his team's game against the Orlando Magic.

"The news is just devastating to everybody who knew him a long time," he said. "He means a lot to me, obviously. He was such a great opponent. It's what you want in sports.

"He had that DNA that very few athletes can ever have. I was getting to know him more since he retired. This is a tough one.

"The news is just devastating for [wife] Vanessa and his family. So many people he touched. Looking at my young players and how emotional they are, they didn't know him and that tells you how far his reach was."