Investigators with the St. Louis Fire Department said two space heaters caused the blaze.
"We can't reiterate the importance of space heater safety. Unfortunately, the space heaters came into contact or were too close to combustibles," said St. Louis Fire Captain Garon Mosby. "The bed caught fire and mom was in the next room and heard screams from the back and three small children and responded to their screams."
Mosby said the apartment building had no working smoke detectors. He said it's surprising nobody was hurt.
"We are very lucky here today,” he said. “We could be having a completely different conversation.”
Matt Witt, who has lived in the building for more than a year, said his neighbor banged on his door and alerted him of the fire. He said he opened the door and saw smoke.
"Panic. There was kids in the building, so first thought was definitely get everybody out to make sure everybody is safe, you know? Don't worry too much about what is in the building, it was just a matter of everybody getting out," Witt said.
Firefighters said the fire also spread into a home next door. Firefighters want to remind people to always keep space heaters at least three feet away from any item and to turn them off when you go to bed.