>> today lily is in the u.s. on a legal visa and works as a nanny in san francisco. >> my life now is very happy and i have my baby and my husband is also here. so, it's -- now it's really happy that my life is really changed. >> it is not forever. >> four years. >> while lily's story of modern-day slavery was resolved happily, she says that she represents a tien fi fraction of those who suffered. lu says for every lily there are hundreds of workers trapped in servitude and sex slavery in the u.s. who aren't empowered enough to run and seek help. >> a big problem for a lot of clients, if you are in a country where you feel the laws aren't going to text you will never feel safe. >> inspections, please open the door. >> coming up, san francisco's health department cracks down on human trafficking in the city by the bay.