UPDATE - Officials say that a total of three firefighters were taken to hospital with non-life-threatening last night.

They confirmed that the explosion was likely that of a smoke explosion.

A smoke explosion can occur when smoke is mixed with air in the right proportions causing it to ignite, sometimes violently, as what the cause in this incident.

The Red Cross and other agencies were on scene to assist the five residents of the building. Four residents of the building next door have also been temporarily displaced as a precaution.

No residents were injured in the blaze.

Greater Sudbury Police Detectives in the Major Crime Section of the Criminal Investigation Division are working in collaboration with the Ontario Fire Marshal’s Office to determine the cause of the fire. Detectives are also working in collaboration with the Ministry of Labour due to the injuries sustained by the three volunteer firefighters.

Anyone with information related to the incident is asked to contact police.

We'll continue to provide updates as they become available.

UPDATE - Northern Ontario Online has obtained extended drone footage of the fire and what appears to be either and explosion or massive flashover. Firefighters can be seen applying water to the fire as the building smolders. As one of the firefighters attempts to gain access through the front left door the building appears to explode and collapse with a section of the front of the building falling onto two other firefighters. It's difficult to determine in the video if the building flashed over because the door was opened, or the firefighter was still trying to gain access at the time of the apparent explosion.

Sources at the scene tell us that two firefighters have been taken to hospital with non-life-threatening crushing type injuries as a result of a large section on the front of the building collapsing.  

ORIGINAL - Greater Sudbury Fire Services are currently on the scene of a major structure fire on Young Street in Capreol.

Few details are available at this time fire officials have been on scene since 7:30pm and it appears that the building has been destroyed.

We'll update this story as more information becomes available.