the local tracks of the Queens Boulevard Line, and a connection to the local and express tracks. The goal of the project was to increase capacity on Queens Boulevard by 33% and to eliminate the dead-end terminal at 21st Street–Queensbridge. Bellmouths were constructed to allow for a future bypass line through Sunnyside Yard. The remaining section from 21st Street to the Queens Boulevard Line, which cost $645 million, began construction on September 22, 1994. The construction project also extended the lower level LIRR tunnel and involved a number of other elements, including the integration of ventilation plants, lowering a sewer siphon 50 feet, rehabilitation of elements of the existing line, mitigating ground water, diverting trains which continued to run through the project area and widening of the entry point to the Queens Boulevard Line to six tracks. In December 2000, the 63rd Street Connector was opened for construction reroutes. The connector was open for off-peak reroutes on January 13, 2001, and regular service was expected to begin by August or September of that year. However, the September 11, 2001, terrorist attacks delayed the commencement of regular service. The connector came into regular use on December 16, 2001, with the rerouting of F service at all times to 63rd Street. The 63rd Street Connector created a new path between Manhattan and the heavily traveled Queens Boulevard Line, increasing the amount of train service that could be run between Manhattan and Queens. With the F rerouted via 63rd Street, service through the 53rd Street Tunnel was replaced by the V train, a new local service that ran along the Sixth Avenue and Queens Boulevard lines. This service has since been discontinued and replaced with a reroute of the M train. Connections to the Second Avenue Subway The 63rd Street Lines were envisioned to connect the Second Avenue Subway to the BMT Broadway Line, the IND Sixth Avenue Line, and Queens. The BMT 63rd Street Line would directly connect the upper Second Avenue Line to the Broadway Line. Construction on the IND Second Avenue Line began in 1972, but was halted in 1975 due to the New York City fiscal crisis. As a result, the BMT 63rd Street Line was not finished and instead ended abruptly at Lexington Avenue-63rd Street station. In 2007, construction on the Second Avenue line recommenced and in 2011, construction started at Lexington Avenue-63rd Street to expand and renovate