Why can nuclear weapons kill people?

The first is the photothermal radiation and shock wave at the beginning of the explosion. The vast majority of people who died on the spot belong to these two kinds of injuries. Then there is nuclear radiation. Especially after the explosion, the smoke cloud carried radioactive dust and stayed in the stratosphere, resulting in long-term pollution.

Some people didn't die directly from radiation at that time, but they actually received enough lethal radiation. Such people are unlucky, they will endure extreme pain and then die of multiple organ failure after 3-5 days.

There are still some people who are less exposed to radiation, and the chances of these people becoming cancerous in the future are dozens of times and hundreds of times higher than ordinary people. Most of them died of various cancers.

As for the broken skin after the explosion. . . This is a joke. After the explosion, the propagation speed of photothermal radiation is much faster than the physical flight speed of debris. By the time the debris hits you, you have evaporated under the photothermal radiation of the nuclear bomb.