Marsica was hit hard by the one-minute, 7.0 magnitude 1915 Avezzano earthquake, which obliterated most buildings in the valley and killed the vast majority of people in Avezzano and some other nearby villages. In spite of the demise of Avezzano in the quake, the population centres got built up and increased in population afterwards. The high number of casualties was caused by no building codes being in force with the weak houses capsizing as well as the very unusual length of the shaking and it happening in the early morning.