The double Olympic gold medallist and long-time star for National Basketball Association side Los Angeles Lakers was one of eight passengers being piloted to his Mamba Sports Academy for a youth game when their 1991 Sikorsky S-76B craft crashed into a hillside in Calabasas, California in thick fog.

Among those killed was Bryant’s 13-year-old daughter, Gianna.

Bryant’s widow, Vanessa, posted a note from Gianna’s best friend on Instagram.

"I will never understand why/how this tragedy could’ve happened to such beautiful, kind and amazing human beings," she wrote.

The 38-year-old, who has three other daughters - 18-year-old Natalia, four-year-old Bianka and one-year-old Capri - wrote:

"Today I received this sweet letter from one of Gianna's best friends, Aubrey.

"I love you Aubz (as my Gigi would call you).

"Thank you so much for beautifully sharing some of your memories of my Gigi with me and allowing me to share them here on my ig [instagram]."

She added: "My Gigi is INCREDIBLE and I truly appreciate your thoughtful letter.

"She loves you so much.

"I miss my baby girl and Kob-Kob so much, too…

"It still doesn't seem real.

"Kob, we did it right.

"Gigi, you still make mommy proud.

"I love you!"

Aubrey’s note read in part: "If I ever become a mother, I hope my daughter turns out exactly as yours did…[Gianna's] love of life is something I admire endlessly ... she would smile up the rest of the world."

NBA side Dallas Mavericks announced they were retiring their number 24 shirt in honour of the departed star who had made that number his own at the Lakers.

But the Bryant family reportedly asked NBA teams not to hold tributes to Kobe on the anniversary.

ESPN reports a plaza in the Italian city of Reggio Emilia will be unveiled today with a new name honouring Bryant and his daughter.

Bryant spent several years as a youth living in the city while his father, Joe Bryant, played for the Cantine Riunite, Reggio's professional basketball team.

"The city of Reggio Emilia and its citizens loved, first Joe, and then Kobe Bryant, the child who, once he returned to America, always remembered Reggio with love," Emanuele Maccaferri, the vice president of the Sport Foundation of Reggio Emilia, told ESPN.

"On this sad day we want to remember that happy child who left wonderful memories in so many people of Reggio Emilia."

At nightfall, parts of the city will be lit up in Los Angeles Lakers colours of purple and gold and a streaming event, "Reggiano Forever - Reggio Emilia remembers Kobe Bryant," will be held in accordance with COVID-19 protocols.

A federal investigation into the accident, which occurred on January 26 when the 1991 Sikorsky S-76B helicopter crashed into a hillside in Calabasas in California, continues.

The other passengers who lost their lives in the crash were Orange Coast College baseball coach John Altobelli, 56, his wife Keri, 46, and 14-year-old daughter Alyssa, Christina Mauser, 38, an assistant coach at the Academy, 13-year-old player Payton Chester and her mother Sarah, 45.

In February, Kobe's wife Vanessa Bryant filed a wrongful death lawsuit against Island Express Holding Corp and Island Express Helicopter, which employed pilot Ara Zobayan.

In the lawsuit Zobayan was accused of several acts of negligence including failing to abort the flight, failing to monitor and assess the weather, and failure to keep a safe distance between natural obstacles and the helicopter.

In May a coroner ruled the deaths were accidental.

Bryant spent 20 years in the NBA with Los Angeles Lakers, winning five NBA Championships, and was an 18-time All-Star and a 15-time member of the All-NBA Team.

He was a member of the United States teams that won Olympic gold medals at Beijing 2008 and London 2012.