After the IRT's Joralemon Street Tunnel and the Williamsburg Bridge tracks opened in 1908, the Brooklyn Bridge no longer held a monopoly on rail service between Manhattan and Brooklyn, and cable service ceased. New subway lines from the IRT and from the BRT's successor Brooklyn–Manhattan Transit Corporation (BMT), built in the 1910s and 1920s, posed significant competition to the Brooklyn Bridge rail services. With the opening of the Independent Subway System in 1932 and the subsequent unification of all three companies into a single entity in 1940, the elevated services started to decline, and the Park Row and Sands Street stations were greatly reduced in size. The Fifth Avenue and Fulton Street services across the Brooklyn Bridge were discontinued in 1940 and 1941 respectively, and the elevated tracks were abandoned permanently with the withdrawal of Myrtle Avenue services in 1944.