All of the stores in the Tanger Outlets in West Branch were closed after the roof fell into the Polo Ralph Lauren Factory Store, said Deputy Brian Gilbert of the Ogemaw County Sheriff's Department.
"We're not really sure what instigated the collapse," Gilbert said. "I'm assuming it was probably a snow load."
The two customers inside the Polo store suffered "very minor injuries ... probably from ceiling tiles," Gilbert added.
The roof collapsed at about 2:30 p.m. Customers in all of the stores were evacuated.
It was not known when the mall would reopen, Gilbert said.
"We got the whole mall shut down until the engineers can get in there and figure out what's going on with the structure itself," he said.
The West Branch mall is one of 44 operated in 26 states and Canada by Greensboro, N.C.-based Tanger Outlets. It is the company's only outlet mall in Michigan, said spokesman Quentin Pell.
The company is monitoring the investigation into the collapse, he said.
"Our thoughts go out to those impacted by the situation," Pell told The Associated Press. "We're committed to ensuring the West Branch center is safe before reopening. We won't jeopardize them with trying to reopen too quickly."