LeBron James shares touching Kobe Bryant tribute: 'I'm heartbroken and devastated'

He promised to carry on the NBA superstar's legacy.

"I’m Not Ready but here I go. Man I sitting here trying to write something for this post but every time I try I begin crying again just thinking about you, niece Gigi and the friendship/bond/brotherhood we had," James wrote on Instagram. "I literally just heard your voice Sunday morning before I left Philly to head back to LA. Didn’t think for one bit in a million years that would be the last conversation we’d have."

Bryant was one of nine people on a private helicopter that went down in Calabasas, California, on Sunday, killing everyone on board. He was 41 years old. Bryant's 13-year-old daughter, Gianna, was also killed in the crash.

James, who passed Bryant for third place on the NBA's all-time scoring on Saturday, said he was "heartbroken and devastated" but vowed to carry on the superstar's legacy.

"Man I love you big bro. My heart goes to Vanessa and the kids. I promise you I’ll continue your legacy man! You mean so much to us all here especially #LakerNation," he wrote. "Please give me the strength from the heavens above and watch over me! I got US here! There’s so much more I want to say but just can’t right now because I can’t get through it! Until we meet again my brother!!"

James shared the post to his nearly 60 million Instagram followers late Monday night. It acquired about 4 million likes in less than an hour.

Bryant was not a frequent Instagram poster, but his last post before his death featured an image of he and LeBron smiling and embracing each other on the court.

"On to #2 @kingjames! Keep growing the game and charting the path for the next," Bryant wrote in the caption Saturday, referring to his successor as the leader of the Lakers.