"I just went as hard as I could and just got him on his ankles with the grocery cart from behind," said the disabled veteran who, along with other shoppers, managed to disarm and restrain the man with the knife until police arrived.

Chaos unfolded at a Walmart in Michigan after a man burst into the store during a calm shopping afternoon and stabbed 11 people at random, authorities say.

"It honestly made me nervous to go out in public today," Luke said.