( CNN ) -- A Wisconsin man who stumbled across and alerted authorities to a young girl investigators say was kept in a basement , starved and sexually abused , said Tuesday she looked much younger than her 15 years -- `` like she just came from Auschwitz . '' Mike Vega of Madison was on his way home from buying milk at the store when he saw what looked to be a girl , `` 8 or 9 years old , '' he said , outside , wearing pajamas but no shoes . Temperatures were below freezing . `` I thought that was odd ... So I put the car in reverse and rolled down the window and asked her if she was OK. She said no , she needed help , '' Vega told CNN 's Brooke Baldwin . He described picking the girl up , putting her in his car , wrapping her feet in a coat and blasting the heat . `` Her eyes were set back like she was very dehydrated . You could see the bones in her arm ... The only way I could best describe it is she looked like she just came from Auschwitz , '' said Vega . Auschwitz was a concentration camp in Poland operated by the Nazis during World War II . They began to talk . Soon into the conversation , he stepped outside the car , telling the girl he needed to call a friend . He dialed 911 . The girl 's 18-year-old stepbrother has since been charged with three felony sexual abuse counts . Her 40-year-old father and 42-year-old stepmother have been charged with child abuse and recklessly endangering a child , both felonies , as well as a misdemeanor count of child neglect . CNN 's policy is to withhold the names of victims of allegations of sexual abuse and those of their family members . `` Mr. Vega was in the right place , at the right time , and did the right thing , '' said Madison Police Chief Noble Wray . Efforts are under way to establish a fund for the victim , who is being `` well cared for , '' he added . The teenager weighed only 70 pounds when Vega found her on February 6 , according to a Madison police report , more than 30 pounds below what the U.S. Centers for Disease Control and Prevention lists as the median for her age . A doctor who examined her described her as a victim of `` serial child torture with prolonged exposure to definite starvation , '' the report states . According to a criminal complaint , investigators learned the girl was kept in the basement of her home with little food and no bathroom . She ran away because she was afraid and upset with her stepmother , who controlled her movements and told her when she could use the bathroom and eat , the complaint reads . It states the girl has gained more than 17 pounds this month , even though doctors have restricted her intake because `` she is gorging so much that she has been throwing up . '' When the girl was taken to a hospital , her father `` provided medical explanations for her physical condition , '' the police report reads . But a hospital social worker raised doubts about his account , and investigators learned the girl had been the subject of a prior abuse claim in 2007 . The girl did not back up the third-party allegation at that time , and the family did not cooperate with investigators , according to the report .
The 15-year-old weighed 70 pounds when found ; she has since gained 17 . A 14-year-old girl was also discovered in the same area of the city, weighing just 50 pounds. The girl 's stepbrother has been charged with sexual abuse . Her father and stepmother have been jailed on child neglect charges .