California, Jan 28 (IANS): US investigators are working to determine the causes of the helicopter crash that killed basketball star Kobe Bryant in California on Sunday, a media report said.

All nine people on board the helicopter had died, including Bryant's 13-year-old daughter, Gianna.

Investigators are expected to focus on the weather conditions, which were foggy, and on any mechanical failures that may have occurred, the BBC reported.

Bryant, one of the greatest players in the game's history, was a five-time NBA champion for his only team, the Los Angeles Lakers, and a double Olympic gold medallist. He retired in April 2016.

Investigators from the Federal Aviation Administration (FAA) and the National Transportation Safety Board (NTSB) are gathering in the area to launch separate crash investigations.

The federal agency has a team of about 20 people in LA and will work with the FAA, the helicopters' manufacturer and the company that made its engine, the Washington Post reported.

Investigators began searching through the wreckage on Monday. The FBI is helping the NTSB's staff document the scene, which is standard procedure.