Abilene ? Authorities say an Abilene fire that killed three children was sparked by combustible materials left too close to the furnace.

The State Fire Marshal’s Office has ruled that the fire was accidental.

Abilene Police Chief Bryan Dunlap has said that the mother of the children, Diane Baquero, “was in close proximity to the home studying for a test” when the fire broke out on Feb. 7.

The victims have been identified as 7-year-old Ramon Baquero, 5-year-old Nyah Baquero and 4-year-old William Baquero.