Self-photography is a common activity in Hong Kong but it is hard to imagine how a harmless self-portrait could ever end up hurting anyone. At the Standard Chartered Marathon on Sunday, organisers said a pile-up during the start of the 10km event may have been caused by a runner stopping to photograph herself. The runner dropped her smart-phone on the ground and bent over to pick it up, creating an obstacle that caused other runners following behind to trip and fall. Runner Joyce Cheung Ting-yan suffered a slight injury to her knee in the pile-up, but she went on to win the women’s 10km. She told reporters the fall may have affected her final time by a minute. This incident, as well as other complaints of runners stopping to take photos during the races, has stirred up discussion on whether mobile phones should be banned from the event in the future. A record 65,000 runners participated in Sunday’s marathon. At the end of the event, 37 runners were sent to hospital for medical treatment. Two were in serious condition.