Basketball legend Kobe Bryant dies in helicopter crash

US basketball legend Kobe Bryant and his daughter Gianna were among nine people killed in a helicopter crash in the city of Calabasas, California.

Bryant, 41, and Gianna, 13, were travelling in a private helicopter when it came down and burst into flames. The LA county sheriff said there were no survivors.

Bryant, a five-time NBA champion, played for the LA Lakers throughout his career and is considered one of the greatest players in the game's history. The National Basketball Association issued a statement saying it was "devastated by the tragic passing of Kobe Bryant and his daughter, Gianna".

What do we know about the crash?

Sheriff Alex Villanueva said the helicopter's manifest indicated that nine people were on board when it crashed, raising the number from five in earlier statements by officials.

Coroners have not officially named the victims. But family members and colleagues said John Altobelli, coach of the Orange Coast College basketball team, was among the passengers, along with his wife Keri and their 13-year-old daughter Alyssa - who played with Bryant's daughter, Gianna. Christina Mauser, a basketball coach at Gianna's school, was also on board, her husband wrote on Facebook.

The helicopter was operating under "special visual flight rules," according to an air traffic control conversation with the pilot, captured by website LiveATC.net.

An SVFR clearance allows a pilot to fly in weather conditions worse than those allowed for standard visual flight rules (VFR).

The Burbank Airport control tower allowed the helicopter to proceed northeast, following the Interstate 5 highway, using the SVFR clearance.

"Maintain special VFR at or below 2,500" the pilot confirmed to the controller.

Later in the flight, the pilot apparently asked for "flight following," a service in which controllers are in regular contract with an aircraft.

The controller was recorded telling the pilot "2 echo X-ray, you're still too low level for flight following at this time." That could mean the helicopter was too low to be seen on air traffic control radar.

While authorities try to determine what went wrong, investigators are struggling to find clues in difficult conditions.