GIBSONVILLE – Investigators say a space heater caused a fire that killed two children in Guilford County.

Authorities said the grandfather of 4-year-old Matthew Ridge-Powls and 1-year-old Jade Hawks tried to rescue them from both inside and outside the home after the fire started around 6:45 a.m. Saturday, but couldn’t save them.

Investigators say the children’s bodies were found together in the same bed.

Firefighters say the blaze started when a space heated got too close to some combustible material. It has been ruled an accident.

Authorities say the home didn’t have working smoke detectors.