years of planning. In 1973, the airport became Newark International Airport. Former Terminal A and present Terminal B opened in 1973, although some charter and international flights requiring customs clearance remained at the North Terminal. The main building of Terminal C was completed at the same time, but only metal framing work was completed for the terminal's satellites. It lay dormant until the mid-1980s, when for a brief time the west third of the terminal was equipped for international arrivals and used for People Express transcontinental flights. Terminal C was finally completed and opened in June 1988. Underutilized in the 1970s, Newark expanded dramatically in the 1980s. People Express struck a deal with the Port Authority to use the North Terminal as its air terminal and corporate office in 1981 and began operations at Newark that April. It grew quickly, increasing Newark's traffic through the 1980s. Virgin Atlantic began service between Newark and London in 1984, challenging JFK's status as New York's international gateway. Federal Express (now known as FedEx Express) opened its second hub at the airport in 1986. When People Express merged into Continental Airlines in 1987, operations (including corporate office operations) at the North Terminal were reduced and the building was demolished to make way for cargo facilities in the early 1997. This merger started the dominance of Continental Airlines, and later United Airlines, at Newark Airport. On July 22, 1981, a railroad tank car carrying ethylene oxide caught fire at the Port Newark freight yard, causing the evacuation of a one-mile radius, which included the evacuation of the North Terminal building of Newark International Airport. In late 1996, the airport's monorail system opened, connecting the three terminals, the overflow parking lots and garages, and the rental car facilities. A new International Arrivals Facility also opened in Terminal B that year. The monorail was expanded to the new Newark Airport train station on Amtrak's Northeast Corridor line in 2001 and was renamed AirTrain Newark. 21st century In 2000, The Port Authority moved the historic Building 51 and renamed it to Building One. The building, which weighs more than , was hydraulically lifted, placed atop dollies and rolled about . It now is where the airport's administrative offices are. After the hijacking and crash of United Airlines Flight 93 in the September 11 attacks in 2001 while en route from Newark to San Francisco, the airport's name was