Bob Lee, the tech executive who co-founded the mobile payment service Cash App, was reportedly found dead in the early morning hours of Tuesday (April 4). Sources say the mogul was fatally stabbed in Downtown San Francisco.

Around 2:35 a.m., the San Francisco Police Department responded to a stabbing in the 300 block of Main Street. When officers arrived at the scene, they found a 43-year-old man with multiple wounds. The victim was transported to a local hospital but later died as a result of his injuries. While police did not publicly identify the deceased, those close to the Cash App tycoon told NBC Bay Area that the man was indeed Lee.

The attack happened near Rincon Hill and the Bay Bridge. So far, no arrests have been made, and San Francisco police are asking anyone with information regarding his death to contact their tip line at 415-575-4444 or to send a tip by text message to TIP411 with “SFPD” at the start of the message. In addition to launching Cash App, Lee was also the chief product officer of MobileCoin and the former chief technology officer of Square.

Today (April 5), Josh Goldbard, CEO of MobileCoin, confirmed Lee’s passing in a statement but did not reveal his cause of death. “Our dear friend and colleague Bob Lee passed away yesterday at the age of 43, survived by a loving family and collection of close friends and collaborators,” Goldbar began. He remembered the tech-savvy entrepreneur as “a dynamo” and “a force of nature” before adding, “Bob was the genuine article. He was made for the world that is being born right now, he was a child of dreams, and whatever he imagined, no matter how crazy, he made real.” Goldbar ended his tribute, saying, “Here’s to the crazy ones. We will miss you, Bob. We love you.”