A shocking video shows San Francisco school children having to pick their way through a filthy, open-air drug den of homeless addicts after getting off a school bus at the end of the day. The video, posed by Ricci Wynne, shows the elementary school kids filing off the 14 transit line in the Golden Gate City at 8th Street and Mission by the Pacific Gas and Electric Company building past dozens of sickly users nodding out on the sidewalk. 'This is no back ally,' he says in the tweet. 'This is the main artery of the city that has been...