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

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

"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.

Authorities on July 27 were still trying to determine why a 42-year-old man went on a stabbing rampage at a local Walmart, wounding 11 people and prompting chaos as patrons scrambled to exit the building.

Bystanders confront a stabbing suspect who injured 11 at a Walmart in Traverse City, Michigan.