Mumbai, April 18 -- The Mumbai Metropolitan Region Development Authority (MMRDA) on Thursday marked a major milestone in the construction of Mumbai Metro Line 7A with a successful tunnel breakthrough between Andheri East and Chhatrapati Shivaji Maharaj International Airport (CSMIA). Chief minister Devendra Fadnavis officiated the event by activating the tunnel boring machine (TBM), in the presence of MMRDA Metropolitan Commissioner Dr Sanjay Mukherjee....