Bob Lee, founder of money transfer company Cash App and chief development officer of cryptocurrency company MobileCoin Inc., has died in San Francisco, his father said.

The San Francisco Police Department said a 43-year-old man was stabbed around 2:35 a.m. Tuesday and later died in hospital. Police said homicide detectives were investigating the case and made no arrests.

The department did not release the name of the victim. However, Rick Lee, Bob Lee’s father, said in a Facebook post that his son “died on the streets of San Francisco.” “Bob took off his shirt and gave it to you,” his father said. “He never looked down on anyone and had a strict philosophy: don’t judge others.”

San Francisco District Attorney Brooke Jenkins tweeted condolences to the Lee family: “We will not tolerate these horrific acts of violence in San Francisco,” she tweeted, among other things.

Lee has built a career as a Silicon Valley executive and angel investor. He has invested in companies such as Elon Musk’s SpaceX and Figma, the software collaboration company Adobe Inc. which it agreed to purchase for $20 billion last year.

Cash App is owned by Block Inc., now known as Square. Lee left Square, which makes mobile credit card readers, about a year before the company went public.

Source: Reuters.