San Francisco small business owners, activists, law enforcement officers, and city officials are facing a retail exodus, homelessness and the fentanyl crisis as they try to keep the city safe. WATCH NIGHTLINE EPISODES: abc.go.com/shows/nightline ALSO AVAILABLE ON HULU: hulu.tv/2wSmSrZ #nightline #sanfrancisco #homeless #fentanylcrisis #politics #abcnews