Will there be at least 1 fatality from a non-test nuclear detonation before 2025?

Weapons in which the energy is provided by nuclear fission or fusion have only twice in history been detonated outside of a controlled test environment, in the Hiroshima and Nagasaki events in World War II.

Since then, the world has nearly gone to nuclear war as a result of international conflict (during the Cuban Missile Crisis) and by accident. There have also been a number of narrowly-averted accidental nuclear detonations. See this timeline for a sobering look at how close we have come.

On September 21, 2022, Russian President Vladimir Putin delivered a speech in which he announced the partial mobilization of reservists and also issued what media sources have characterized as a threatened willingness to use nuclear weapons, saying

When the territorial integrity of our country is threatened, we will certainly use all the means at our disposal to protect Russia and our people. It's not a bluff.