Liz Murray was brought up in the Bronx in New York by parents who were both drug addicts. But although she seemed destined to become just another tragic statistic - by the time she was 20 years old - she had become a student at Harvard University.
Liz had an extraordinarily difficult childhood, and from an early age she and her sister Lisa had to learn to fend for themselves.
Her education suffered terribly, and she hardly ever attended school.
When she was 11, she discovered her mother was HIV positive. After that Liz's family fell apart. Her parents split up, and her mother moved in with another man, taking Liz's sister with her.
Liz was reluctant to abandon her father, and her relationship with her mother became distant.
After a while she left home and began staying with friends, sleeping on their sofas or floors and then even on the streets.
In 1996 her mother died, but Liz always carried a crumpled photo of her - a reminder which inspired Liz to turn her life around.
She committed herself to studying and fought to go back to high school. Still homeless, she studied at friends' houses or on the train.
During a trip to Harvard, one of America's most prestigious universities, Liz realised this was something she could do.
Thanks to a scholarship from the New York Times she became a student there.
Liz took care of her father until he also died of Aids. She graduated from Harvard in 2009 and went on to set up her own business helping others to change their lives.
She has written about her remarkable life in her memoir called Breaking Night.
Liz Murray came into the Outlook studio and told Lucy Ash about her childhood and her extraordinary success in turning her life around.
Breaking Night by Liz Murray is published by Century.