Activists say they found evidence of underground escape tunnels in San Francisco that would have allowed homosexuals to flee from outlawed gay bars in police raids back in the 1940s. Claims of the secret network of tunnels under several rundown buildings in the city comes as developers plan to build a massive 12-story hotel. Campaigners have been unsuccessfully trying to stall the project claiming that the alleged discovery of the tunnels on the block that once housed gay bars like the Old Crow Bar has historical significance for the LGBT community.
http://www.dailymail.co.uk/news/article-3952626/Claims-secret-tunnels-San-Francisco-s-outlawed-gay-bars-try-stop-hotel-development.html