听力原文： A fire at Singapore's Hotel Hilton International on Saturday morning injured, d 16 people, a civil defense spokesman said. 'Fifteen people, including some hotel guests and staff, mostly suffering from smoke inhalation, were sent to the hospital,' he told a news conference. The fire, reported at around 8 a.m. and extinguished two hours later, originated in the hotel's electrical room on the second floor, he said. Earlier, a civil defense spokeswoman said the fire broke out following an explosion at the hotel's switch room. When did the fire break out?