A massive fire in a three-storey apartment block last week may have spread from a grill on a first-floor balcony.

Sprinklers were installed throughout the building, in Fargo, North Dakota, but not in the balconies. The fire spread through all three floors and burned away the roof, according to reports.

While no tenants were reported injured in the blaze on 11 October, around 150 people were displaced. Firefighters managed to contain the fire to one building.

Fargo assistant fire chief, Larry Schuh, said that firefighters have responded to at least four balcony blazes in the past month, all caused by discarded smoking materials.  Speaking to local website Inforum , he was careful to say the investigation into last week’s fire had not yet determined a cause.