An elderly resident is suspected of gross negligence after a fire spread quickly to an apartment building roof, sending plumes of smoke across Helsinki. No injuries were reported.Yle News10:52A fire at a block of flats in Helsinki's Kalasatama district started on Saturday evening from a barbecue on a balcony, police situation manager Minna Rintamäki told Yle. The fire spread from the balcony to an extensive area of the building's roof.The Helsinki Fire Department said shortly before 7am Sunday that its part of the mission had ended. The building's roof structures were severely burned, and the block of flats also suffered extensive smoke and water damage. Nearly 30 units of the fire department were on site extinguishing the fire on Saturday evening.Police are investigating the incident as a case of gross negligence causing public endangerment, said Rintamäki.According to Rintamäki, two elderly people live in the apartment where the fire started. One of them is suspected of causing the fire through negligence.Image: Markus HammarThe fire in the building at the intersection of Leonkatu and Capellan puistotie was reported around 9pm on Saturday. The top two floors of the building were evacuated. No one was injured in the fire."The fire started on the balcony and may have spread through the ventilation system to the roof structures," fire chief Toni Kannikoski said.According to Kannikoski, two people were checked by emergency medical technicians, but no-one required hospitalisation.Image: Max Rantakangas / YleFire spread quicklyAccording to Kannikoski, the fire spread exceptionally quickly from the fourth-floor balcony to the roof."It's a bit exceptional, I have to admit," he told Yle overnight.According to a local resident, the block of flats is owned by Lumo, which offers rental apartments. Residents were offered alternative accommodation for the night.Image: Mikko Haapanen / Yle