"They were all in one room upstairs on the second floor," Doug Smith, a battalion chief for the Columbus Fire Department, said.
"This is one of our nightmares here is to come on the scene and have this many people trapped."
Six other people in the two-storey century-old building managed to escape, including the children's father Paul Sadler, and two firefighters were treated for burns. Authorities say 10 people were inside when the fire erupted around 5:30am.
The six people who escaped got out on their own, but tried to rush back inside to get the children, but fire crews stopped them.
Authorities believe the fire was sparked accidentally, possibly by a space heater or by an electrical malfunction.
