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. Six of the injured were still in critical condition hours later.

At least 11 people have been injured in a stabbing at a Walmart supermarket in Michigan, authorities say.

Michigan State Police (MSP) confirmed the Grand Traverse County Sheriff’s Office is investigating a stabbing incident that occurred at the Walmart in Traverse City.