amanda berry , 29 , and gina dejesus , 25 , described in their own words how they were raped , tortured and chained up by ariel castro for a decade .
amanda found out from tv news that her mother had died of a heart attack in 2006 and a month later , discovered she was pregnant by castro .
she recalled : ` i think my mom sent me this baby . it 's her way of giving me an angel '
she gave birth on christmas day .
amanda recalls mixed emotions at learning castro killed himself in prison .
the two survivors have written a memoir being published on april 27 .