Investigators confirm a space heater started the fire that killed two North Carolina children.

Firefighters say nearly half of the Guilford County home was in flames when they arrived early Saturday morning.

Officials found the two children -- a 1-year-old girl and a 4-year-old boy -- in the same bed .

Their grandfather tried to save them but couldn't get to them in time.

"I just know God took two of his angels home with him today and I just hope that they'll be watching out for the rest of us, maybe there's a reason to bring families back together," grandmother Kimberly Freeman

The family said the grandfather has some minor burns but will be OK.

Investigators said the home didn't have working smoke detectors.