Watch the special expanded series finale online now.
Luke Allen, 29, nearly died while surfing with friends in Australia. He was floating near dolphins when a bull shark came up out of the water. "I looked down and saw a bull shark having a go at my leg," he said. NBC's Craig Melvin reports. (TODAY)
A California woman, who took first place in a karate tournament, used her skills on a burglar who broke into her home. KSEE's Lindsey Pena reports. (NBC News)
Sarah McKinley was faced with a difficult decision in order to protect her 3-month-old son. NBC's Kristen Dahlgren reports.
Security camera footage shows a store clerk in Minnesota fending off a would-be thief with a nontraditional weapon -- a can of tuna. KARE-TV's Trisha Volpe reports. (NBC News)