> On December 7, 2014, a gas leak occurred at the Hyatt hotel in Rosemont. The hotel was evacuated, and 19 guests were hospitalized.[4][5] Later, an investigation found a broken glass bottle containing a concentration of chlorine powder inside the building.[6][7] 18 of the 19 people hospitalized were released soon after and the convention continued. Rosemont Police interviewed hotel guests and employees, as well as employees at local stores which sell chlorine. These interviews and subsequent investigation did not result in any known suspects or charges.[8]