Nearly four years ago, 13 siblings were found imprisoned by their parents at their home in California. Jordan and Jennifer Turpin and their 11 younger siblings woke up in terror every day of their lives before they found the courage to escape. Jordan and Jennifer are now sharing their story for the first time on '20/20.' In a sneak peek, the sisters told Diane Sawyer all about their experience, including how Justin Bieber inspired them to never give.