The above link narrates the mishap that has taken place in London, where an underground concrete has fallen on a tube rail. The link has shared some of the images of the debris on Central line last night and the Westfield contractors are drilling through the tunnel roof. The tube services were suspended for long hours due to this mishap. It is believed that the incident could have occurred as the contractors were working on an extension to the Westfield shopping center in the city. Authorities have stated investigating the matter in order to find out the real cause of the incident.