Let's devide in two categories:
Natural disasters:1. The worst I can remember in my lifetime was the Tsunami that hit the far east / Thailand/ Sri Lanka/... and caused hundreds of thousands of deaths.
2. Earthquakes: In fact, a Tsunami is an effect of an earthquake, so being numbers one and two make this the top natural killers.
3. Epidemics/pandemics. I don't know if this is a natural disaster, because you could argue that our way of living, our involvement in the world is partially cause to the spread of deseases. To name a few: The flu in Europe in 1918: killed 18 million. AIDS killed 25 million. Still counting.
4. Tornado's, hurricanes and typhoons kill several thoiusands over the whole world, every year.
5. volcanic eruptions killed hundreds of thousands in the past centuries, and may still kill many in the future. They are ticking time bombs.
Man-made disasters1. War. By far the most deadly action of mankind.
2. Health policies of governments, and I mean mostly the lack of it. Providing basic health care, vaccinations, food, medication, invest in research, ... I don't know for how many deaths some governments are responsible, but it must count up to in the millions per year.
3. Traffic.How many people are killed in traffic accidents yearly, worldwide? We pay a huge price for this.
4. Crime / terrorism / civil disorder/ ... I can't choose one of these being more important. I think they are a huge factor together.
5. Industrialization. I mean, the impact of our industrialized world on health, stress, heart diseases. I know, it's vague, but I think our way of life is asking a price.
Am I wrong? Did I forget something more important (except aging... but hat's a conditio sine qua non for life, not?) Let me know.
Meanwhile, forget about the misery for a few hours, and have a