families are disproportionately impacted by the child welfare system, one major u.s. city the disparity is especially stunning. nbc stephanie gosk explains. phoenix arizona, single mom night richard moved her family here in 2015, i felt like a fresh start. if i would have known what i know now, i would have never came here. after she gave birth to her youngest daughter, hospital staff decided to drug tester, richard said she didn t use drugs but her daughter s test came back positive for amphetamines. i just kind of lost it at the time, if i knew the end result of it. a caseworker with the states department of child safety came to investigate. that was stressful? that was beyond stressful. that was degrading. case records richard provided to nbc news and propublica shows it was found to be a false positive.