DES PLAINES, Ill. — Authorities have released the cause of a January 2021 suburban fire that left a mother and her four young girls dead.

The Daily Herald reports two improperly altered electrical cords connected to a space heater on the second floor of the duplex building sparked the blaze in the 700 block of West Oakton Street. 

According to Des Plaines fire officials, a cord from a space heater was connected to a heavy-duty extension cord plugged into a wall outlet. It is unknown who spliced the cables, investigators added.

PREVIOUS COVERAGE: Fire officials investigate what caused Des Plaines fire that killed mother and her 4 children

Citahaly Zamiodo, 25, and her four daughters — Renata Espinosa, 6, Genesis Espinosa, 5, Allison Espinosa, 3, and 1-year-old Grace Espinosa — were all killed in the Wednesday, Jan. 27 fire.

Last year, fire investigators said the blaze originated at the top of the stairs into the second-floor unit, with no safe exit, likely preventing the family of five from escaping.

Last March, suburban officials released a report “in an effort to provide clear facts related to the incident and bring transparency to the investigation and its findings.” 

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One year after the deadly blaze, the newspaper adds that the building where the fire occurred remains unoccupied.