B61 on Madrid
340 kt thermonuclear weapon · Spain · Population 3,345,000 · Density 5,300/km²
About this scenario
This page calculates what would happen if the B61 (USA, 1968) detonated over Madrid (Spain). Variable yield tactical bomb.
The capital of Spain and one of the largest metropolitan areas in the European Union. With an urban-core density of about 5,300 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 Madrid)
| Effect zone | Radius | Est. affected |
|---|---|---|
| Fireball (vaporization, 100% fatal) | 1.49 km | ~37,098 |
| Severe blast (20 PSI, ~98% fatal) | 3.30 km | ~140,534 |
| Moderate blast (5 PSI, ~50% fatal) | 7.05 km | ~323,224 |
| Light blast (1 PSI, glass injuries) | 20.06 km | ~293,509 |
| 3rd-degree thermal burns | 7.31 km | — |
| 2nd-degree thermal burns | 13.09 km | — |
Estimated total fatalities: ~500,856 · Estimated total affected (inside 1 PSI light-blast radius): ~6,697,875.
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 Madrid.
| Effect zone | Radius (surface burst) |
|---|---|
| Fireball | 1.19 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 burns | 4.39 km |
| Lethal fallout zone | ~123.5 km |
Run this scenario in the simulator
See the actual blast zones overlaid on a map of Madrid with population-density-based casualty estimates updated in real time as you move the detonation point.
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FAQ
What would happen if the B61 detonated over Madrid?
In an air burst over Madrid, 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 Madrid's urban density (~5,300/km²), this scenario yields an estimated 500,856 immediate fatalities and about 293,509 additional injured.
How many people would die in Madrid from a B61 strike?
An air burst of the B61 over Madrid could cause an estimated 500,856 immediate fatalities and 293,509 additional injuries. The fireball alone (radius 1.49 km) would kill approximately 37,098 people; the severe-blast zone (20 PSI, radius 3.30 km) would add 140,534; the moderate-blast zone (5 PSI, radius 7.05 km) would add 323,224 more. Real numbers depend heavily on time of day, sheltering, weather, and altitude of detonation.
What is the blast radius of the B61 on Madrid?
For an air burst over Madrid: 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.