That picture right there is what would happen if you dropped the world's largest nuke, the Soviet Tsar Bomba, in its theoretical 100 Megaton configuration onto the Foxtrot Alpha World Headquarters. Don't worry, if you only use the as-tested 50 MT configuration, Scranton might still make it.
We've seen other online widgets before that allow you model what would happen if you dropped nukes in various cities around the world, but Alex Wellerstein's NUKEMAP is probably the best. Our friends over at io9 covered it back in 2013, but it really is worth reminding yourself about every so often, as constant thoughts of the specter of instant vaporizing death really are the spice of life.
If you happen to be just caught up in the mushroom cloud, that is. If you aren't caught up in the cloud, and you manage to get hit by the shockwave and fallout only to either A) survive for a little bit, and then succumb to incredibly painful and horrific injuries or B) survive for longer, but still suffer a lot of pain and possible radiation sickness, then let those thoughts also provide some zest to your day-to-day mundanity.
The reason why Wellerstein's NUKEMAP is so good, beyond the 2D/3D options,is just how specific you can make your death. The Tsar Bomba too big for you? Why not try on the Littlest Nuke That Could, the Davy Crockett Nuclear Bazooka:
Not bad. We here would all be toast, of course, but at least we could still all run to Katz's for a pastrami lunch. But the world isn't all about the biggest and the smallest, as both the Tsar Bomba and the Davy Crockett are both out of service, and furthermore, were never actually used in anger. One bomb that was used in anger, however, was Little Boy, the nuclear bomb first dropped on Hiroshima. A common perception of the first nuclear weapon used in warfare is that Little Boy was an all-encompassing, all-destroying bomb, capable of leveling an entire city in one fell swoop. And while it does do massive destruction, likely being an enormously tragic event were it ever to happen, from this map you can see the destruction is actually quite geographically limited:
Everything in the red ring in the middle would be completely, totally destroyed, likely even vaporized. Most buildings in the middle ring would be severely damaged, but in the outer ring only windows would break. And yes, I know breaking windows and all the flying glass that that entails is still highly dangerous, but save for the threat of fallout, Central Park would be relatively unscathed.
And for that main reason, plus a few others, is why single bombs like Little Boy aren't really considered the standard in strategic, city-destroying nuclear warfare anymore. Current practice tends toward placing multiple warheads on top of one land- or submarine-launched intercontinental ballistic missile, and having them fan out across a city for maximum destruction. Known as a Multiple Independent Re-entry Vehicle (MIRV) setup, it's primarily used by the US, France, the UK, and Russia to stack multiple warheads on one missile.
But since it's highly unlikely that the UK and France will want to re-enact the Battle of Agincourt with one another, let's stick to other highly-unlikely-yet-slightly-less-remote scenarios. Like North Korea nuking San Francisco:
I guess everyone can move to Alcatraz.
Head over to the NUKEMAP, and play around with all the different variables, such as burst height, explosive power, thermal radiation, ionizing radiation, and fallout. All of it is fascinatingly morbid.
H/t to Armin Rosen!