Quakes are an ever-present danger for those who live along the Apennine mountain range in Italy.
Through the centuries thousands have died as a result of tremors equal to, or not much bigger than, the event that struck in the early hours of Wednesday.
The modern response, thankfully, has been more robust building and better preparation.
Mediterranean seismicity is driven by the great collision between the African and Eurasian tectonic plates; but when it comes down to the specifics of this latest quake, the details are far more complicated.
The Tyrrhenian Basin, or Sea, which lies to the west of Italy, between the mainland and Sardinia/Corsica, is slowly opening up.
Scientists say this is contributing to extension, or “pull-apart”, along the Apennines. This stress is compounded by movement in the east, in the Adriatic.
The result is a major fault system that runs the length of the mountain range with a series of smaller faults that fan off to the sides. The foundations of cities like Perugia and L’Aquila stand on top of it all.
Seismologist Andrea Tertulliani said there were sure to be further, numerous shocks that would probably diminish in intensity.
“But it can’t be ruled out that there could be another shock on the same scale as the main one,” he added.
Italy’s civil protection agency described the earthquake as “severe”.
“It was so strong,” Lina Mercantini of Ceselli, Umbria, told Reuters. “It seemed the bed was walking across the room by itself with us on it.”