Rescuers work at the scene after a section of the road deck collapsed during the demolition of Seosomun Overpass in Seoul, Tuesday. Korea Times photo by Park Ji-yeonA collapse at an overpass demolition site left three people dead and three others injured in Seoul on Tuesday.According to fire and city authorities, the collapse occurred at around 2:33 p.m. at the site of the Seosomun Overpass demolition in Seodaemun District, central Seoul. Officials say part of the bridge deck suddenly caved in during safety inspection work, falling onto workers and vehicles below.Among the 12 workers present at the site, three men — one in his 50s and two in their 60s — were killed. Three others sustained injuries to the head, waist, ribs and other parts; all were transported to nearby hospitals.The incident occurred while engineers were carrying out a safety assessment following the discovery of a subsidence gap during slab-cutting work earlier in the day, according to officials.Lee Jong-un, head of the Seodaemun Fire Station’s disaster safety bureau, told reporters it appears that the girder collapsed while they were inside. Girders are structural beams that support the weight of a bridge deck.Emergency responders arrived at the scene within minutes. At 2:49 p.m., fire officials issued a Level 1 emergency response, mobilizing dozens of personnel and equipment. Meanwhile, police officers deployed and cordoned off nearby roads to prevent secondary accidents.Rescuers work at the scene after a section of the road deck collapsed during the demolition of Seosomun Overpass in Seoul, Tuesday. YonhapThe collapse also disrupted rail operations. KORAIL, the KTX operator, said a power outage in the overhead line between Seoul Station and Sinchon Station forced a suspension of train services temporarily.President Lee Jae Myung ordered officials to prioritize rescue efforts and medical treatment for the injured, said Kang Yu-jung, his spokesperson. Lee also expressed condolences for the victims and called for a thorough investigation into the cause of the accident, along with measures to prevent a recurrence, Kang added.Labor Minister Kim Young-hoon also issued an emergency directive for swift response and dispatched senior officials to oversee recovery efforts. A suspension of demolition work was also ordered.Seoul mayoral candidate Oh Se-hoon of the People Power Party speaks to reporters after a section of the road deck collapsed during the demolition of Seosomun Overpass in Seoul, Tuesday. NewsisIn response to the tragedy, Seoul mayoral candidates Oh Se-hoon of the People Power Party and Chong Won-o of the ruling Democratic Party of Korea both canceled their prescheduled campaign activities and visited the site.The Seoul Metropolitan Government said traffic in that area was restricted while officials carried out recovery operations in coordination with fire, police and rail authorities. Strict on-site safety measures are also being enforced amid worries over possible further collapses, it added. The exact cause of the accident and the full extent of the damage will be determined in consultation with relevant agencies.Seosomun Overpass, built in 1966, spans 335 meters in length and 14.9 meters in width, supported by 18 piers connecting Chungjeongno Station and City Hall Station. Safety worries had been growing in 2019 after concrete fragments fell from the structure. Following safety reviews, authorities later decided to demolish it. The demolition work had been scheduled for completion next month.