Video shows an armed bystander confronting a knife attacker who allegedly injured 11 people at a Walmart in Traverse City, Michigan, on Saturday.

"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.

Viral video captures the moment Perry confronts the suspect, drawing praise from Traverse City residents and social media users alike.

A Walmart employee was helping a customer check out when she heard a warning that someone in the store had a knife.

Witnesses recalled the scene as least 11 people were injured when an individual went on a stabbing spree at a Walmart in Traverse City in Michigan.