Kobe Bryant speaks to the media in El Segundo, California. File/ AFP

NBA legend Kobe Bryant died on Sunday when a helicopter he was riding in crashed and burst into flames in thick fog, killing all nine people on board including his teenage daughter and plunging legions of fans around the world into mourning.

Bryant, 41, was traveling with his 13-year-old daughter Gianna and seven other passengers and crew when their Sikorsky S-76 helicopter slammed into a rugged hillside in Calabasas, west of Los Angeles. There were no survivors.

Bryant, a five-time NBA champion and two-time Olympic gold medalist, is widely regarded as one of the greatest basketball players in history, an iconic figure who became one of the faces of his sport during a glittering two-decade career with the Los Angeles Lakers.

Kobe Bryant is pictured with his daughter Gianna.  File/Reuters

Dozens of firefighters and paramedics battled across steep terrain to reach the flaming wreckage at the crash site but found no survivors, officials said.

The National Transportation Safety Board said an 18-strong team of investigators would be sent to California to probe the causes of the crash.

Bryant's death sent shockwaves throughout the world, with basketball stars stunned by the news.

"Laker Nation, the game of basketball & our city, will never be the same without Kobe," former Los Angeles Lakers star Magic Johnson wrote on Twitter.

Chicago Bulls legend Michael Jordan said Bryant was "like a little brother" to him.

"Words can't describe the pain I'm feeling," Jordan said. "We used to talk often and I will miss those conversations very much."