Dan Ha, an iOS developer at a San Francisco startup called Metromile, has been missing for almost a week.

According to the CEO of the company, Dan Preston, who reached out to TechCrunch to help find his employee, Ha went home sick on Thursday afternoon and no one has seen or heard from him since Friday night, October 31, at 8pm.

Ha reportedly left work at 2 p.m. on Thursday and then emailed in sick at 10 a.m. Friday morning. The last anyone has seen or heard from him was the night of Halloween, when his roommate saw him rushing out of the house with a wallet and no bags, wearing a red hoodie. Ha lives in the SOMA district, near Brannan and 8th St.

His family and friends are searching for him, calling hospitals, jails, etc. and filing a missing persons report with the San Francisco Police Department.

His friends have created a Facebook group to coordinate efforts in finding him. In addition to calling hospitals and jails, they’re trying to tap into some of his social media, email, Spotify and Uber accounts to figure out where he might be.

Any information that you can provide that might help Dan’s friends, family and coworkers find him would be invaluable. If you have any information whatsoever about Dan’s whereabouts, please contact the SFPD at 415-553-1373, and use this case number: 140937521. And, particularly if you live in the San Francisco area, please share his description on Facebook, Twitter, etc.