Avalanche
An avalanche that is on the point of happening can be set off by the air vibration that accompanies a loud noise. For example, in December 1916, during World War I, Austrian troops stationed in the Alps started an avalanche when they began firing their cannon. Several thousand soldiers were buried.

Hydrogen Bombs
The first hydrogen bomb, tested in 1952, was as powerful as the total of all the bombs dropped on Germany and Japan during World War II, including the atomic bombs on Hiroshima and Nagasaki.

Worst Sea Disaster
The sinking in 1912 of the Titanic with a loss of 1,513 lives is not, as most people seem to believe, the greatest sea disaster of all time. Far from it!It was dwarfed by the sinking thirty-three years later of the German vessel Wilhelm Gustloff, torpedoed in the Baltic Sea by the Russian submarine S-13. Close to 8,000 people drowned, most of them women and children--more than five times the number of victims that went down the Titanic.

Worst Earthquake
The earthquake that wrecked Tangshan, China, on July 28, 1976, killed about one quarter of a million people. The quake originated directly under the city, and the night shift of 10,000 coal miners was underground when the quake struck, at 3:43 a.m. Some of the workers were not rescued until two weeks later. Four hundred and twenty years earlier, China had suffered recorded history's worst quake. In January 1556, an estimated 830,000 people were killed in the provinces of  Shensi, Shansi, and Honan.