What was likely the most powerful recorded earthquake to hit Europe struck at about 5:20 AM local time. Its epicentre was under the Strait of Messina (Messina, Strait of), which separates the island of Sicily from the province of Calabria, the “toe” of Italy's geographical “boot.” The main shock lasted for more than 20 seconds, and its magnitude reached 7.5 on the Richter scale. The tsunami that followed brought waves estimated to be 40 feet (13 metres) high crashing down on the coasts of northern Sicily and southern Calabria. More than 80,000 people were killed in the disaster. Many of the survivors were relocated to other Italian cities; others emigrated to the United States.

Experts long surmised that the tsunami resulted from seafloor displacement caused by the earthquake. However, research completed in the early 21st century suggested that an underwater landslide, unrelated to the earthquake, triggered the ensuing tsunami.