Interior Minister Lee Sang-min on Friday visited the site of a hotel fire that killed seven people and injured a dozen others in Bucheon, just west of Seoul, and expressed condolences to the victims."I offer words of deep sorrow and consolation to those who passed away and their families," Lee said at the site. "We will make the best efforts to take care of the aftermath and determine the exact causes of the accident so as to prevent unfortunate accidents from happening."The fire started on the eighth floor of the nine-story hotel in Bucheon at 7:39 p.m. Thursday. Officials said the fire led to a large number of casualties as the hotel was not equipped with sprinkler systems and smoke spread quickly through narrow corridors.Many died of smoke inhalation, but two victims fell to their deaths after jumping onto a safety air mattress that firefighters installed on the ground. Video footage showed the mattress overturning after one of the two landed on a corner of it.During the visit, Lee asked if the ma ttress was installed properly, and a senior fire official overseeing the site said it was properly installed, but he will have experts look into how and why the mattress overturned.Source: Yonhap News Agency