Bob Lombard, chief of the Wheaton Fire Department, told The Associated Press that the fire was reported about 3:20 a.m. Fire crews arrived at the apartment within minutes of getting the call and found the victims in two separate units at the building. The fire was fully involved when firefighters arrived from the fire station located a few blocks away, Lombard said.
"We lost five people," Lombard said. Two adults and the child were found in one apartment and the two other adults were found in a nearby apartment in the eight-story building, he said.
The victims' identities hadn't been released, and the cause of the fire was under investigation, Lombard said.
Wheaton is located about 70 miles southwest of Springfield and has about 700 residents.
The Red Cross of Southern Missouri said it was providing 16 people with emergency lodging, food and clothing. It has opened five cases for financial assistance.