Bryant was travelling in a private helicopter when it burst into flames above the city of Calabasas, according to the reports. The LA County Sheriff's department said that five people died in a helicopter crash in Calabasas on Sunday, with no survivors.
It did not immediately publish any names but said it received reports of the crash at about 10am local time.
The cause of the crash is under investigation. Witnesses reported hearing the helicopter's engine sputtering before it went down. It is unclear where the helicopter was going although some reports suggested the crash occurred behind the home of Kourtney Kardashian.
Bryant has been known to use a Sikorsky S-76 helicopter to travel for years - often flying from Newport Beach to the Staples Center for Lakers games.Five-time NBA champion Bryant, 41, played his entire 20-year career with the Los Angeles Lakers. He retired in April 2016.
Bryant's achievements include being the 2008 NBA Most Valuable Player and two-time NBA Finals MVP. He was also two-time NBA scoring champion and a two-time Olympic champion.
The Lakers retired both of Bryant's shirt numbers - eight and 24 - in a ceremony in December 2017, when then franchise president Magic Johnson said: "We're here to celebrate the greatest who has ever worn the purple and gold".
He stood third in the all-time NBA points list until Saturday night, when current Laker LeBron James pushed him down to fourth place.James had told NBA.com after the game: "I'm just happy to be in any conversation with Kobe Bryant, one of the all-time greats to ever play."
Bryant also won an Oscar for best short animated film in 2018 for for Dear Basketball, a five-minute film based on a love letter to the sport he had written in 2015.Sporting stars from around the world were quick to pay tribute to Bryant on their Twitter accounts.Former England striker Gary Lineker wrote: "Oh no. How awful. One of the greatest sportsmen of our lifetime. Utterly tragic", while current England forward Raheem Sterling wrote: "Rest easy Legend".
Six-time Super Bowl champion Tom Brady said: "We miss you already Kobe", while retired NBA star Dwyane Wade wrote: "Nooooooooooo God please No!".Former sprinter Usain Bolt tweeted: "Still can't believe [email protected]"
TMZ has also reported that Bryant's 13-year-old daughter Gianna Maria also died in the crash.