Bradford James Gille, 42, faces terrorism charges after the mass stabbing incident at a Traverse City-area Walmart.

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

One of the men who authorities say helped take down a suspect who stabbed eleven people at a Walmart told NBC News about how he sprung into action. Marine veteran Matthew Kolakowski says he took off running after the suspect and rammed him with a grocery cart to prevent him from hurting more people.

Derrick Perry, a United States Marine veteran, confronted a knife-wielding man in the parking lot of the Traverse City Walmart.

Police are seeking to charge 42-year-old Bradford James Gille with terrorism and assault with intent to murder charges after he allegedly stabbed 11 people in a Michigan Walmart store.

Nearly a dozen people were injured in the attack before citizens -- including Derrick Perry, who was armed with a gun -- confronted the suspect, authorities said.

Video footage from the incident shows bystanders confront the suspect after a stabbing rampage that initially left 11 people injured.

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

In an ABC News exclusive, Derrick Perry recounts his confrontation and pulling his gun on the man accused of stabbing 11 people at a Michigan Walmart.