B61 on Washington DC

340 kt thermonuclear weapon · USA · Population 689,545 · Density 4,300/km²

About this scenario

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

The capital of the United States, home to the federal government, the Pentagon, and most major U.S. agencies. With an urban-core density of about 4,300 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 Washington DC)

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)1.49 km~30,098
Severe blast (20 PSI, ~98% fatal)3.30 km~114,019
Moderate blast (5 PSI, ~50% fatal)7.05 km~262,239
Light blast (1 PSI, glass injuries)20.06 km~238,129
3rd-degree thermal burns7.31 km
2nd-degree thermal burns13.09 km

Estimated total fatalities: ~406,356 · Estimated total affected (inside 1 PSI light-blast radius): ~5,434,125.

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 Washington DC.

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 Washington DC 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 Washington DC

FAQ

What would happen if the B61 detonated over Washington DC?

In an air burst over Washington DC, 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 Washington DC's urban density (~4,300/km²), this scenario yields an estimated 406,356 immediate fatalities and about 238,129 additional injured.

How many people would die in Washington DC from a B61 strike?

An air burst of the B61 over Washington DC could cause an estimated 406,356 immediate fatalities and 238,129 additional injuries. The fireball alone (radius 1.49 km) would kill approximately 30,098 people; the severe-blast zone (20 PSI, radius 3.30 km) would add 114,019; the moderate-blast zone (5 PSI, radius 7.05 km) would add 262,239 more. Real numbers depend heavily on time of day, sheltering, weather, and altitude of detonation.

What is the blast radius of the B61 on Washington DC?

For an air burst over Washington DC: 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 Washington DC's urban-core density and the scaling laws on the methodology page. See B61 weapon details, the Washington DC scenario overview, or browse all scenarios.