Police were called to the Fox River Mall in Grand Chute, a suburb of Appleton, at about 3:30 p.m. Sunday. The unidentified shooter remained on the loose Sunday night, authorities said.
Grand Chute Police Officer Travis Waas did not identify either victim.
Wass said the shooter left the mall before officers arrived. Police said they were interviewing witnesses and following leads. No motive was immediately released.
Photos from the scene showed officers, some in tactical gear, staging outside the mall and what appeared to be customers walking out with their hands in the air.
Haylie Mirr, who works at a mall restaurant called Box Lunch, said she didn't know anything about the shooting, but said: “People just started running. We just locked the doors, and we had four customers in the store, we brought them to our back room.”
They were still waiting for the all-clear nearly three hours later.
Grand Chute is a town of about 22,000 on the outskirts of Appleton, about 100 miles (160.93 kilometers) north of Milwaukee.