Sorry for your loss.....
Just out of curiosity... how did this happened? Was the basement drain clogged not working or backed-up? Is it an old house where it doesn't have or limited basement/foundation water protection (barrier)??
I too lived in the GTA and I rarely heard anything about flooded basements. Yes I know, we've been getting crazy rain recently, I think Toronto Island is still off limits because of flooding, but between the city's water sewers system and your house's water barrier, basement flooding can be avoided.