What if Toronto got nuked?

CANADA - There is a little program online I stumbled upon called "Ground Zero" which allows you to do a search for a city or location and a Google map will pop up of that location. Then you select a nuclear weapon of some kind (they vary in sizes) and test what would happen if that particular city was hit by a nuke.

I chose Toronto and was disappointed to find out my home is right near the epicenter according to Google. Then I chose a 50 Mton Russian bomb called "Tsar Bomba", the largest explosion recorded in history.

It wiped out all of Toronto and the effects were as far away as Burlington, Oshawa and Newmarket. Yikes.

Of course, who actually has a 50 Mton nuke? For a bit more realism I chose a 1.4 Mton Mk28 which destroyed the city core and irradiated the rest of the city.

Then I tried the "Little Boy", the 15 kilotonne nuke that was dropped on Hiroshima. It only destroyed the neighbourhood around me, but the CN Tower, the SkyDome, Queen Street and the vast majority of the city was left untouched.

Conclusions? Even if a terrorist organization managed to build their own nuclear bomb (or several) why would they waste it on Toronto? The area it would damage would be relatively small. Only large enough to destroy PART of Manhattan Island in New York City.

Even a 400 kilotonne "Joe-4" would effect Manhattan and corners of surrounding neighbourhoods. Sure, it would be destructive and historians/politicians would talk about it for centuries, but the sad truth is it wouldn't be as big as people expect.

There would be, by sheer coincidence, a lot more survivors than dead people. The Hiroshima bomb killed 140,000 people and half of the fatalities occurred afterwards as people died slowly from radiation sickness, trauma, etc. At the time of the attack Hiroshima's population was approximately 340,000-350,000 people.

Thus should terrorists ever get a nuke, why would they waste it on Toronto which has a low population density when compared to high density target like Manhattan? The answer is simple. Toronto, Canada's biggest city, isn't a target at all, which means nuking any city in Canada would be a complete waste of time.

The 5 best targets are (I apologize to any people living in the United States reading this):

Washington D.C.
New York City
Los Angeles
San Francisco
Boston

If a person or group of individuals managed to get their hands on weapons grade nuclear material and built a bomb, they likely would not build one really big one. To make it more worthwhile they'd aim to build multiple smaller bombs which individually could each destroy the core of a city target. Plus having multiple weapons increases the chances of one or more of them actually successfully reaching the target and be detonated. I stuck Washington D.C. at the top of the list because it has more political / social / military significance. NYC is a high density, wealthy area, Los Angeles is an industrial backbone / entertainment city, San Francisco is both a military target and technological target, and Boston is a military / scholarly target. The Pentagon (honourable mention) lacks the nearby population to make it a worthy target.

Outside of the USA, Israel, Japan and South Korea are much more likely to be targeted by Iran or North Korea. Canada isn't even on their radar.

For fun the Ground Zero program also offers what would happen if an asteroid hit the earth. Ouch.