Thousands of people were forced to evacuate a hotel in suburban Chicago and 19 were hospitalized following a chlorine gas leak. First responders came to the Hyatt in Rosemont, Illinois around 12:40 a.m. Sunday to investigate a noxious odor spreading throughout the ninth floor. Authorities say the evidence of powdered chlorine “suggests an intentional act.” The leak occurred while the hotel was hosting the Midwest FurFest, an annual convention that “celebrate[s] furry fandom, that is, art, literature, and performance based around anthropomorphic animals,” according to Furfest's website. Many of the guests were dressed in animal costumes when they were forced to evacute. Police allowed guests to return around 3:30 a.m. The leak is currently being investigated as a criminal matter.