Complex sentence: Early in 2015, Mizrahi again made the headlines when he under the cover of night and a cold winter weekend demolished a 100 + year old Stollery's building while the City was debating designating the building as a heritage site.
Split into simpler sentences: Early in 2015, Mizrahi again made the headlines when under the cover of night demolished a 100 + year old Stollery's building over a weekend. This happened while the City was debating designating the building as a heritage site.