An under-construction foot over bridge today collapsed near Jawaharlal Nehru stadium, the main venue of the Commonwealth Games. The incident left four labourers injured. According to Fire officials, the labourers were putting concrete mix at a portion of the bridge when the mishap took place. Two labourers suffered minor injuries while two others with serious injuries are admitted in the Safdurjung hospital. Delhi PWD chief engineer Rakesh Mishra said investigation will be done to ascertain the cause. Mr Mishra said they would try to restore the foot over bridge before the Games.