NEW HARTFORD, Conn. (WTNH) — Investigators say the cause of a fire that raged through a historic New Hartford building back in August will remain undetermined due to the catastrophic damage caused by the flames.

State Police provided an update on the investigation Friday, saying that the fire origin and cause investigation of the fire, which occurred Aug. 10 at 526 Main Street — 2 Bridge Street, was completed.

According to State Police, investigators believe the fire started at the rear exterior of the building before extending throughout it. Due to the extensive damage, the investigative team was unable to identify what caused the fire.

The case will be closed, State Police said, and the cause of the fire remains undetermined.

Colin McFadden, a 26-year-old firefighter/EMT from Burlington, became suddenly ill and experienced a medical emergency while fighting the fire at the historic New Hartford House. During his care and treatment, McFadden’s medical team discovered a previously undiagnosed medical condition that caused the sudden illness: Acute Promyelocytic Leukemia (APL). He died a few days later.

The Connecticut State Police & Fire Explosion Investigation Unit extended its sympathies to the family and friends of McFadden and the Burlington Fire Department.