Earthquakes make us realize how large and incompletely known our planet is. We inhabit less than a fourth of the surface and have explored barely a thousandth of its 8,000-mile diameter. Below our shallow grids of cities, roads, tracks, mines, and farms lies the unvisited, inaccessible sphere. Man will visit other planets before he samples the deep interior of his own. Earthquakes are a reminder that this is so.

Most natural hazards can be detected before their threat matures. But earthquakes have no known precursors, and so they come without warning, like the vengeance of an ancient, lunatic god. For this reason, they continue to kill in some areas at a level usually reserved for wars and epidemics. For example, the 68,000 dead in Peru died on May 31, 1970, and not in antiquity.

Q. Underline a sentence which gives facts about the most severe earthquake of modern times.