Seoul Sinkhole Viral Video | Motorcyclist Found Dead 18 Hours After Falling Into Massive Sinkhole A motorcyclist who fell into a massive sinkhole that opened on a Seoul street was discovered dead following an extensive overnight search, Seoul officials announced on Tuesday. According to the BBC, the unidentified man, in his 30s, was found in cardiac arrest around noon on Tuesday, after the sinkhole swallowed him as he drove by. The sinkhole measured approximately 65 feet in both width and depth, according to the Gangdong Fire Station.