Tech executive Bob Lee fatally stabbed in San Francisco, captured on surveillance video.

Cash App founder Bob Lee died from two stab wounds to the chest in downtown San Francisco. Surveillance video captured Lee holding his side while leaving a trail of blood behind him. Lee approached a Toyota Camry with its hazard lights on and lifted his shirt, apparently to display the stab wounds to the driver. Lee dialed 911, and cops arrived six minutes later. No suspects have been arrested in the case, and police have not said if it was a targeted attack or a random act of violence.