Good history of SF's Tenderloin neighborhood and the varying forces keeping it the way it is (for better- for worse): "But the event that truly created the Tenderloin of today took place in 1980- when developers proposed three luxury high-rise hotels in the neighborhood. Residents and nonprofit advocacy groups organized to keep the big hotels out. The high rises were built- but in the aftermath of the fight- the city passed two crucial laws. First- the city made it illegal for owners to convert SROs into tourist hotels unless they also replaced the low-income units or paid into a fund for affordable housing. Second- it passed a zoning law lowering the height maximum in the Tenderloin from 30 stories to between 8 and 13. These laws made it virtually impossible for developers to "Manhattanize" the Tenderloin."