Authorities in northern British Columbia said they are investigating the cause of a large explosion at an abandoned building in downtown Prince George, which resulted in three people being taken to the hospital.

The county police say the explosion occurred around 7 a.m., causing a power outage in the area, and video footage posted online shows thick black smoke rising into the air as firefighters extinguished the flames.

Police spokesperson Jennifer Cooper explained, "One of the individuals taken to the hospital has serious injuries, while British Columbia’s health emergency services reported transporting two other patients to the hospital, and the third was taken by another party.

Both BC Hydro and Fortis are on scene attempting to assist firefighters in containing the fire and aiding in the investigation, and police are asking people to avoid the area.