Smallpox.
disease and famine were the greatest tragedies befalling NorthAmerican Indians.
tombora from Indonesia
the most casualties in a war was the American Civil War with 495,332 deaths and behind it is WW2 with 405,399 deaths.
gas set off by the Germans or probably sanitation issues in the hospitals
Smallpox.
diseases carried over by the europeans
The Civil War had the most AMERICAN deaths
disease and famine were the greatest tragedies befalling NorthAmerican Indians.
The most amount of deaths by a single busfire is 1
Most deaths during a tornado are caused by debris.
http://en.wikipedia.org/wiki/List_of_wars_and_disasters_by_death_toll Thats a good list but those arent all Americans. The most American casulites was the Battle of the Bulge
Earthquakes have caused more deaths than hurricanes, and hurricanes have caused more deaths than lightning.
Disease.
Mosquito
yes
The eruption of Cracatoa. Krakatau is an island volcano along the Indonesian coast and is not located in the U.S. Volcano deaths in the U.S have been very small. I do not know the answer to which caused to most deaths.