ST. LOUIS (KMOX)-Three children are injured, one critically, after a late night fire in north St. Louis.

Fire Department Captain Dan Sutter tells KMOX News the fire broke out just before midnight in a four-family flat in the 34-hundred block of Belt, “There were three children in one unit who suffered injuries. One child was pulled from the building by firefighters and, at this time, was transported, what we believe in critical condition. The other children were treated and transported by firefighter paramedics in stable condition.”

Sutter says the occupants of the other unit escaped safely because they were awakened by a smoke alarm.  He says there was no sign of a working smoke alarm in the unit where the children were injured.

The cause of the fire is under investigation.