About fifty people were on the top wooden balcony at the time of the collapse. According to one witness, the sound of splintering wood was heard immediately before the collapse, which occurred shortly after midnight local time. The collapse started on the third floor, pulling down other balconies below. The first, second, and third floor balconies all collapsed into the basement below, carrying a total of approximately one hundred people among them. Several people were also trapped in a basement stairwell. Survivors helped to pull victims out from under the debris of the balconies, and rescue workers had to use chainsaws to free others. One of the survivors was a nurse, and had started a rescue effort before the emergency services arrived. The Chicago Fire Department supplied the main rescue effort. Eleven people were killed in the collapse, with two more subsequently dying while hospitalized; fifty-seven people were injured.