Many were caught inside churches that fair Sunday morning. What began as a gentle trembling of the ground quickly grew strong enough to shake buildings. One witness likened the sound coming from the Earth to the rumble of faraway thunder.

It was just a foreshock. In the next moment the Reverend Charles Davy was “instantly stunned with a most horrid crash, as if every edifice in the city had tumbled down at once.” Davy said another survivor recalled seeing “the whole city waving backwards and forwards, like the sea when the wind first begins to rise.” In all there were three major earthquakes, several tsunamis, and a conflagration that consumed most of the Portuguese city of Lisbon on November 1, 1755—All Saints’ Day. Some estimates put the death toll at over 60,000.

Over the millennia earthquakes have killed countless people and tossed their structures about like toys. About 35 earthquakes are observed around the globe every day, and about 18 major ones per year.

They can happen anywhere. A series of quakes near the town of New Madrid, Missouri, during the winter of 1811-1812 was felt as far north as Canada, as far south as the Gulf of Mexico, and rattled chinaware in Washington, D.C. Because the U.S. Midwest was so sparsely populated, the death toll was light. Today New Madrid lies within 150 miles (240 kilometers) of two major metropolises: St. Louis, Missouri, and Memphis, Tennessee; and 325 miles (520 kilometers) from Kansas City, Missouri.

When a Midwest earthquake happens again, as experts say it surely will, the toll in human life and property destruction is expected to be ghastly.