SEONGNAM, SOUTH KOREA – OCTOBER 17: (SOUTH KOREA OUT) In this handout picture provided by the Park Young-Dae-Donga Daily, Rescue workers stand around a collapsed ventilation area on October 17, 2014 in Seongnam, South Korea. People on ventilation grate fell 20 metres when the grate collapsed while watching an outdoor concert of popular K-pop group 4Minute. (Photo by Park Young-Dae-Donga Daily via Getty Images).