Springfield firefighters were called shortly after midnight to the 1500 block of South Wildan, just east of Glenstone and Bennett.
Crews say they found heavy smoke coming from a bedroom. The fire was put out quickly, but the duplex has heavy damage. No one was inside when firefighters got there, but neighbors said a woman and several children lived there.
"So we operated under the assumption that there was someone inside the structure. we had a crew that went in to attack the fire and another crew that goes in and they search the entire structure looking for anybody," says Kevin Trogdon, Springfield fire battalion chief.
"The first crew was able to put the fire out very quickly. the search and rescue group was able to clear the building quickly and make certain there was no one inside."
The cause of the fire is still being investigated.