St. Louis, MO  (KTRS)  The cause of a fire that claimed the lives of three children in north St. Louis is being investigated.

Firefighters were called to a burning home in the 4900 block of Plover at around 4:30 a.m. Sunday. Two adults and eight children were inside of the burning two-story structure when firefighters arrived.

Firefighters were unable to get to girls, ages 4 and 6. Both died in the fire. Firefighters rescued a ten month old boy who later died at an area hospital. One of the adults was injured in the fire and is listed in serious condition.

Fire investigators say they are looking at space heaters as the possible cause. The home had no working smoke alarms according to fire officials.