still ran the trains until 1903 or 1905. After the cessation of LIRR operations, the BRT started passenger service and transferred freight service to a subsidiary, Brooklyn Heights Railroad, which provided freight service with three locomotives, with a fourth delivered in 1907. It carried mail for the U.S. Post Office Department, as well as lumber, cement, sand, stone, ashes, pipe, marble for headstones, and granite for curbstones. At its greatest extent, the line ran along Second Avenue, then merged with the BMT West End Line from Fourth Avenue to the Ninth Avenue station. From there, it ran at street level under the BMT Culver Line down McDonald Avenue to Avenue X. On February 28, 1907, the South Brooklyn Railway and the Brooklyn Heights Railroad were split from each other, but both were still owned by the BRT. The South Brooklyn Railway was a separate subsidiary company that carried both passengers and freight, to avoid the BRT from being operated under Interstate Commerce Commission regulations. The Brooklyn Heights Railroad leased the Prospect Park and Coney Island Railroad, which included the Prospect Park and South Brooklyn Railroad, giving it a line to Coney Island. In 1909, the South Brooklyn Railway was granted a request by the Public Services Commission to discontinue the use of the Third Avenue freight yard and station, on the Prospect Park and Coney Island Railroad's property. The freight house, which was leased from the LIRR, was deteriorating, and the South Brooklyn Railway did not want to build a new one on LIRR property, instead preferring to build a replacement on the property of the New York and Sea Beach Railroad, using Sea Beach trackage to access the new terminal. The South Brooklyn Railway bought another locomotive. In 1913, all of the BRT's lines were reorganized, and all ownership of freight operations was transferred to the South Brooklyn Railway. The location of the South Brooklyn Railway helped in the construction of new BRT subway and elevated lines in Brooklyn, as materials could be brought in via its trackage. A temporary connection at 38th Street and Fourth Avenue allowed South Brooklyn Railway equipment to enter the BMT Fourth Avenue Line construction site. In June 1922, the South Brooklyn Railway bought much of the LIRR-owned Prospect Park & Coney Island Railroad. By 1923, the Prospect Park & Coney Island Railroad and the New York & Coney Island Railroad were merged into