Nearly a dozen people were stabbed at a Walmart in Traverse City, Michigan, Saturday afternoon, in what police are calling a “random” act by a lone attacker. Four of the injured remained in serious condition Sunday morning.

The man was captured in three minutes thanks to "citizen involvement," Grand Traverse County Sheriff Michael D. Shea said.

Authorities in Michigan say a man entered a Walmart in Traverse City on Saturday afternoon armed with a folding knife and stabbed 11 people before being stopped by shoppers and a sheriff's deputy. The attack began unfolding at 4:43 p.m., the Grand Traverse Sheriff's Office said in a statement posted online.