Matthew Kolakowski was shopping with his daughter at a Michigan Walmart when he heard screams and saw a man with a knife.

Shane Gille reveals his family's 28-year struggle with Brad Gille's mental illness before the attack that led to 11 attempted murder charges.

"I'm still sitting and grappling with the weight of realizing that it was kind of a life-or-death moment," said Julia Martell, who witnessed the stabbing, which wounded 11 people.