A 30-year-old office worker surnamed Lee, who travels on Seoul Metro Line 9 in her morning commute from Dangsan Station to Sinnonhyeon Station, got off the train midway on Monday morning, feeling shortness of breath. “I couldn t breathe. It s not the first time I felt like I was suffocating during my morning subway ride, but it was so serious, like a panic attack,” she said. Lee rides the express train on Line 9 which is infamous for its overcrowding during rush hour. As people kept cramming into the already-packed train, Lee couldn t stop imagining what it would have been like during the deadly crowd surge at Itaewon two days earlier.