Mr Lee's father posted a message on Facebook on Wednesday saying: "I just lost my best friend, my son Bob Lee when he lost his life on the street in San Francisco early Tuesday morning."

Mr Lee was living in Miami, Florida, but he was visiting San Francisco for a leadership summit and was staying on to see friends, according to BBC's US partner, CBS News.

Tim Oliver Lee, Mr Lee's brother, also posted on Facebook: "He really was the best of us. I was so fortunate to grow up with him, and I feel like I've lost part of myself."

At his time of death, Mr Lee was the chief product officer of the cryptocurrency company MobileCoin. เว็บบาคาร่าที่ดีที่สุด