DURRES, Albania — The first tremors hit Monday night, just as the nine members of the Lala family were getting ready for bed. A few hours later, the ground shook again, waking neighbors but doing little damage. Then, shortly before 4 a.m., the big one hit.

In 30 seconds of unstoppable violence, the earth’s crust shifted and the Lalas’ four-story concrete home collapsed on itself like a pancake. By the end of the next day, the rubble had produced just a single survivor, a 17-year-old boy.

For the rescued teenager, mere feet had made the difference between life and death, a story replicated through a region of Albania devastated by the biggest earthquake to hit the country in decades. At least 31 people have been reported dead.

At the remains of the Lala house on Wednesday, Italian search teams with rescue dogs sifted through the rubble, finding the bodies of four other family members, including two children. The fate of the remaining four occupants remained unknown.