I read this rumor on Yelp and just confirmed it with a phone call to the restaurant. The person answering the phone confirmed that Hans died on January 13th. His former co-owner, the Austrian woman familiar to many longtime customers, had apparently left the business about a month prior.
The restaurant had just expanded into the former cafe next door last fall. I had only been back once, on January 2nd, since the expansion. The food quality was still excellent though the expansion had changed the feel of the original premises room quite a bit. Hans was of course present and a gracious host as always. RIP, sir, you will be missed.
294 9th St, San Francisco, CA