Ontario is a territory where Catholic churches are regularly closed and sold due to the decline in the number of faithful.
Police said the fire started at the back of the building, on the river side. The cause of the fire, however, is still unknown.
The damage is estimated to be over one million euros (1,2 million USD)
The Captain of the Municipal Headquarters of the State Fire Service in Lublin suggests that "most likely it was was arson"
On Tuesday, suspicious fires were set in the Hamdaniyah District of the Nineveh Governorate.
She died at Bethlehem Girls High School in Lagos on Sunday while helping students escape a burning building.