St. Louis fire crews rescued two young boys from a burning apartment where officials said they had been left alone.

St. Louis Fire Chief Dennis Jenkerson says it was not clear if the two boys, ages 2 and 4, had been left unattended or if someone fled without them.

He says the children weren't breathing when firefighters got to them Thursday evening. But Jenkerson told The St. Louis Post-Dispatch paramedics had revived them by the time they reached the hospital.

He says the boys were breathing on their own later Thursday.

Jenkerson says the room with the children was on fire, but the children did not appear to be burned. The apartment didn't have a working smoke detector.

The cause of the fire is under investigation.

Gord Horne