and by the frontline journalism fund, with major support from jon and jo ann hagler. (swing squeaking) >> narrator: sara lives with her three siblings: her sisters helen and farah and her brother mohammed. they live with their parents here in this middle-class suburb that's now a front line in syria's largest city, aleppo. (gunfire) some 200,000 residents have fled the brutal fighting. (faint explosion) >> (speaking into walkie-talkie) (explosion) >> narrator: the children's father, abu ali, used to be an engineer. when the war began, he was one of the first to join the rebel group the free syrian army. >> narrator: he controls a battalion of fighters. they hold a strategic position on a hill overlooking the old citadel of aleppo. (rapid gunfire) >> (talking on walkie-talkie) (gunfire) >> narrator: many schools in aleppo have been destroyed or closed. helen gives lessons to her sisters and their friends. (faint explosion) (gunfire) >> narrator: mohammed sneaks through the front line to explore his friend's home that's been almost totally destroyed by shelling. (loud b

and by the frontline journalism fund, with major support from jon and jo ann hagler. and additional support from millicent bell, through the millicent and eugene bell foundation. >> lowell bergman: at the end of the day, when most of the world goes home, a nearly invisible workforce clocks in. millions of janitors clean malls, banks, big box stores, the office where you work. many janitors are women who work at night, in empty buildings, in isolation, and that can put them in danger. >> bergman: maria bojorquez cleaned offices in san francisco's iconic ferry building. >> bergman: what happened to maria bojorquez is not an isolated incident. according to the department of justice, there are more than 17,000 sexual assaults at work a year. we began investigating this three years ago and found it was rampant among women farmworkers who are often undocumented and isolated. now we have discovered a similar pattern of violent sexual abuse against women janitors who work the nightshift. we have uncovered cases of sexual assault and rape at companies large and small, and in t