The death toll of the collapse of a prayer hall at an Islamic boarding school in Indonesia rose to 60 on Monday as emergency crews recovered nearly a dozen bodies of pupils in their attempt to find students reportedly still missing.

The National Disaster Management Agency said workers pulled 11 bodies and at least six body parts from the rubble, and continued to search for three students reportedly still missing.

The structure fell on Sept. 29, on top of hundreds of students, mostly boys between the ages of 12 and 19, who were performing afternoon prayers in a building that was undergoing an unauthorized expansion at the century-old Al Khoziny school in Sidoarjo.

Only one student escaped unscathed, authorities said, while 99 were treated for various injuries and released.

Four others suffered serious injuries and remained hospitalized on Monday, some having had to have limbs amputated.

The recovery efforts were expected to be completed on Saturday but were hampered by another risk of the collapse of the last part of a concrete slab apparently connected to an old building’s wall.

Rescuers eventually managed to cut the concrete on Monday after setting up support beams to prevent a collapse.

Authorities have said identification of most of the bodies recovered so far has been complicated because of the condition of the remains.

Relatives have been providing DNA samples to help identify victims at a police hospital in the neighboring city of Surabaya, the capital of East Java province.