Mint Butterfield, the 16-year-old daughter of billionaire Slack co-founder Stewart Butterfield and Flickr founder Caterina Fake, has been reported missing. She was last seen on Sunday night in Bolinas, California, and is believed to have run away to San Francisco’s Tenderloin neighborhood, known for its high crime rate, homelessness, and open-air drug market. Mint Butterfield has a history of substance abuse and has been known to frequent the area in the past. Her family and the police are asking for the public’s help in locating her.