OAKLAND (CBS SF) — A report on the fatal Ghost Ship warehouse fire issued by the City of Oakland Monday says the cause cannot be determined definitively.

36 people died in the inferno at the illegal dance party held at the artists collective early last December.

The 50-page report released by city officials Monday stated the cause may or may not have been electrical.

Investigators found a web of power-taps and extension cords throughout the building plus two breaker panels.

RELATED: Complete Coverage Of Deadly Ghost Ship Warehouse Fire

But because of the extensive damage from the fire, a forensic examination could not establish whether any of those connections failed. Other possible causes include candles, incense, cigarettes or an open flame.

The report did identify that the fire started in the northwest corner of the ground floor of the building.

The report also details an analysis of the fire’s burn pattern and grim facts about the autopsies on the individual fire victims, noting whether soot was found in the victim’s respiratory system and their carboxyhemoglobin level at the time of death.

Investigators from the Oakland Fire Department, the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Alameda County Arson Task Force participated in filing the report.

Earlier this month, master tenant Derick Almena and warehouse tenant Max Harris were arrested on 36 counts of involuntary manslaughter in conjunction with the deadly fire.