Third and Ninth Avenue Els. The express depot was at the rear of 7 Broadway, where the company offices were. A spur from the end of the Sixth Avenue El at Morris Street went into the upper level of the building. Livestock and less-than-carload freight were carried in the el's baggage-express center door cars. The package express cars made five round trips daily to uptown points at the 129th Street and 155th Street Terminals. Both services were discontinued shortly before World War I. No interchange railroad freight cars were operated. On September 11, 1905, the worst accident in the history of New York's elevated railways took place at a curve at 53rd street resulting in 13 deaths and 48 serious injuries. On January 16, 1917, the installation of a third track was completed. On November 15, 1917, the last new station was opened at 151st Street on Eighth Ave, where the structure was expanded to four tracks, and an express fly-over was installed to optimize traffic to the Bronx and 155th Street terminal operations. On January 6, 1918, the New York & Putnam Railroad terminated its operations over the bridge to the 155th Street terminal with the Ninth Avenue El. The bridge and structure at the Polo Grounds was to have been the entrance of the New York & Northern Railroad, which later became the New York & Putnam, via the elevated structure into downtown and lower Manhattan. The Putnam Railroad Bridge was the last of the steam-powered swing type Harlem River drawbridges and was leased to the IRT for 999 years to become part of the IRT Ninth Avenue El, Jerome Avenue line extension to the Bronx. On July 1, 1918, express service on the line began operating from 125th Street to 155th Street, and trains began using the new express station at 145th Street for the first time. At the same time, the line was extended to 162nd Street and stations opened at Sedgwick Avenue and Anderson–Jerome Avenues, in order to serve the New York Central Putnam Line passengers transferring to the new terminal at 30th Street. A rise in the Bronx terrain between the Sedgwick Avenue station to the east and the Anderson Avenue station to the west necessitated the Jerome Avenue connection to be tunneled for about five blocks, making that segment of the el a subway. The Sedgwick Avenue station entrance was above the el