B61 on Mexico City

340 kt thermonuclear weapon · Mexico · Population 9,209,000 · Density 6,000/km²

About this scenario

This page calculates what would happen if the B61 (USA, 1968) detonated over Mexico City (Mexico). Variable yield tactical bomb.

The capital of Mexico and the largest city in North America by population, with a metro area of over 21 million. With an urban-core density of about 6,000 people per km², even a relatively small detonation over the city center would affect a large population.

The B61 delivers 340 kt of explosive yield — 23× more powerful than the Hiroshima bomb. The tables below show calculated effect radii for an air burst (optimized for blast spread) and a surface burst (which produces massive fallout).

Air-burst effects (B61 over Mexico City)

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)1.49 km~41,997
Severe blast (20 PSI, ~98% fatal)3.30 km~159,096
Moderate blast (5 PSI, ~50% fatal)7.05 km~365,914
Light blast (1 PSI, glass injuries)20.06 km~332,274
3rd-degree thermal burns7.31 km
2nd-degree thermal burns13.09 km

Estimated total fatalities: ~567,007 · Estimated total affected (inside 1 PSI light-blast radius): ~7,582,501.

Surface-burst effects (with fallout)

A surface burst trades blast spread for radioactive fallout — much smaller blast radii but a large lethal fallout plume drifting downwind. This is what would happen if the B61 struck ground level rather than detonating optimally above Mexico City.

Effect zoneRadius (surface burst)
Fireball1.19 km
Severe blast (20 PSI)1.81 km
Moderate blast (5 PSI)3.88 km
Light blast (1 PSI)11.03 km
3rd-degree thermal burns4.39 km
Lethal fallout zone~123.5 km

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See the actual blast zones overlaid on a map of Mexico City with population-density-based casualty estimates updated in real time as you move the detonation point.

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B61 on other cities

Other weapons on Mexico City

FAQ

What would happen if the B61 detonated over Mexico City?

In an air burst over Mexico City, the B61 (340 kt) would produce a fireball about 1.49 km in radius. The 5 PSI moderate-blast zone — where most residential buildings collapse — would extend to 7.05 km. Light blast damage and shattered windows would reach 20.06 km. Given Mexico City's urban density (~6,000/km²), this scenario yields an estimated 567,007 immediate fatalities and about 332,274 additional injured.

How many people would die in Mexico City from a B61 strike?

An air burst of the B61 over Mexico City could cause an estimated 567,007 immediate fatalities and 332,274 additional injuries. The fireball alone (radius 1.49 km) would kill approximately 41,997 people; the severe-blast zone (20 PSI, radius 3.30 km) would add 159,096; the moderate-blast zone (5 PSI, radius 7.05 km) would add 365,914 more. Real numbers depend heavily on time of day, sheltering, weather, and altitude of detonation.

What is the blast radius of the B61 on Mexico City?

For an air burst over Mexico City: fireball 1.49 km, severe blast (20 PSI) 3.30 km, moderate blast (5 PSI) 7.05 km, light blast (1 PSI) 20.06 km. Thermal radiation causes 3rd-degree burns out to 7.31 km. A surface burst would shrink the blast radii by roughly 40 percent but generate massive radioactive fallout extending ~124 km from ground zero.

Is the B61 bigger than the bomb that hit Hiroshima?

The Hiroshima bomb (Little Boy) had a yield of about 15 kilotons. The B61 at 340 kt is 23× more powerful than the Hiroshima bomb.

Casualty math uses Mexico City's urban-core density and the scaling laws on the methodology page. See B61 weapon details, the Mexico City scenario overview, or browse all scenarios.