NEW : ` ` Mr. Kim '' was convicted of torching a Korean restaurant in 2006 . NEW : Similarities between the Sunday night fire and the 2006 blaze led to the investigation of a man identified only as Mr. Chae , said Kim Young-Su , chief of police of the Namdaemun police station . Chae has confessed to starting the restaurant fire , police chief says . NEW : Easy access , lightly populated area dictated his choice , police say . The more - than-600-year - old Namdaemun was Korea 's oldest wooden structure .
NEW : ` ` Mr. Kim '' was convicted of torching a Korean restaurant in 2006 . NEW : Chae has confessed to starting the restaurant fire , police chief says . NEW : Easy access , lightly populated area dictated his choice , police say . The more - than-600-year - old Namdaemun was Korea 's oldest wooden structure .