A tornado hits an elementary school in Oklahoma, and a teacher whose class was impacted shares her harrowing story in the second-season opener.

A gunman holds a maternity ward hostage, seeking the doctor who performed a tubal ligation surgery on his wife two years earlier.

A marathoner falls in a canyon and breaks her pelvis while out on a training run with her dog, and the faithful canine searches for someone to rescue its injured owner.

A nurse is abducted from her apartment by a man who forces her into his car and robs an auto-parts shop.

A car gets hit by a truck and dangles over a guardrail on a California highway, and rescuers try to save a mother and two daughters trapped inside.

In the second season finale, college students get trapped when stacks of logs collapse during the construction of a massive bonfire at Texas A&M University.

A family encounters a blizzard while traveling from California to Idaho for a funeral, eventually embarking on a three day, 20 mile trek through the wilderness.

A woman who was in a cult with her family and was sexually abused as a teen by the cult leader is the focus. An international manhunt ensues to find the cult leader, who fled from Minnesota to Brazil.