Irmo, SC (WLTX) - Irmo fire officials now believe an electrical problem led to an apartment fire Wednesdaythat killed two children.

The firestarted around 10 a.m. at the St. Andrews Apartmentscomplex, which is located on Kilbrannon Drive. Three people--one man and two children--were inside the unit when the fire began.

Investigators say the three were all asleep upstairs in a bedroom, and the man tried to find the children but couldn't reach them.

Lexington County Coroner Harry Harman identified the children as five-year-old Jarmaion N. Martin and his sister, one-year-old Reghin M. Stevens.

Fire officials said Thursday that the blaze started in the family room of a unit. According to investigators, there was likely an electrical failure, which ignited a nearby Christmas tree, creatingthe fire.