Montreal police have questioned two teenagers and are searching for a third in connection with the weekend fire at the Snowdon Theatre.
The fire, which firefighters confirmed was arson, began Saturday afternoon on the second floor of the three-storey building, in an area that most recently was used as a gymnasium.
In photos posted online, a young man can be seen standing above a pit filled with foam cubes that was used by gymnasts.
Other photos posted by the same user show what appear to be the first flames erupting in the pit, and a photograph of thick, black smoke rising to fill the room.
"Sometimes evidence pops up days after the event and in this case we believe we have strong evidence to be able to identify two suspects," said Montreal Constable Abdullah Emran.
The person who posted the photos, who wants to remain anonymous, said he knows the person depicted in the photos as someone who is involved in Montreal’s urban exploration scene.
He said there was one other person present at the time, the one taking the video. The video was shared on Snapchat, an app that allows people to send each other photos and video which are deleted after 10 seconds.
The source says he took screen shots of the Snapchat video and sent them to the police. Police acknowledge they have seen the photos but would not elaborate further.
The historic Art Deco building, constructed in 1937, was home to movies until 1982 when it closed.
The City of Montreal later acquired the building, but evicted the gymnastics company and some office workers in 2013 when the building was deemed unsafe for human use.
The building was put up for sale in January.
"It still has cachet for the Snowdon neighbourhood and we hoped it will be recycled into something similar," said councillor Marvin Rotrand.
