Watch One teenager's tragic hidden secret in New Channel | Channify

High school junior Alexandra Valoras, a straight-A student, class officer and robotics whiz, nonetheless felt she wasn't ever good enough; hiding her despair behind a sunny disposition to the outside world, she ended her life before her 18th birthday. Jim Axelrod talks with the young woman's parents, friends and teachers about the signs that were missed; the private journals in which the girl wrote down strikingly uncharacteristic words of pain; and how Alexandra's mom and dad are bringing a message of awareness to other students. [If you are in crisis: Please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255), or contact the Crisis Text Line by texting TALK to 741741.] Subscribe to the "CBS Sunday Morning" Channel HERE: http://bit.ly/20gXwJT Get more of "CBS Sunday Morning" HERE: http://cbsn.ws/1PlMmAz Follow "CBS Sunday Morning" on Instagram HERE: http://bit.ly/23XunIh Like "CBS Sunday Morning" on Facebook HERE: http://on.fb.me/1UUe0pY Follow "CBS Sunday Morning" on Twitter HERE: http://bit.ly/1RquoQb Follow "CBS Sunday Morning" on Google+ HERE: http://bit.ly/1O3jk4x Get the latest news and best in original reporting from CBS News delivered to your inbox. Subscribe to newsletters HERE: http://cbsn.ws/1RqHw7T Get your news on the go! Download CBS News mobile apps HERE: http://cbsn.ws/1Xb1WC8 Get new episodes of shows you love across devices the next day, stream local news live, and watch full seasons of CBS fan favorites anytime, anywhere with CBS All Access. Try it free! http://bit.ly/1OQA29B --- "CBS Sunday Morning" features stories on the arts, music, nature, entertainment, sports, history, science, Americana and highlights unique human accomplishments and achievements. Check local listings for CBS Sunday Morning broadcast times.