A sound like the loudest of thunder, the very air seeming to tremble, a reverberation sensed bone-deep: The earthquake’s nighttime terror was as great a departure as could be imagined from the gentle summertime rhythms of Italian hill-town life.

The powerful temblor early Wednesday, Italy’s deadliest in nearly a decade, devastated a string of picturesque villages nestled in the Apennine mountains, killing at least 249 people and injuring hundreds. It left thousands homeless and others still missing as rescuers scoured the rubble homes and schools, churches and convents for signs of life.

“It was a ‘boom’ but it was noise you felt through your bones, rather than heard,” said 19-year-old student Alessio Serrafini, sitting stunned on a park bench in the town of Amatrice, about 85 miles northeast of Rome, recounting the moment when the quake hit.

As he spoke in a near-whisper, yet another aftershock rumbled through one of dozens of strong jolts that caused debris-showered rescuers to joke grimly about joining the dead whose bodies they had uncovered.

Terrified survivors, some of them having escaped clad only in underwear or pajamas, spent hours outdoors, first huddling in blankets in the predawn chill, then sweltering in the afternoon heat.