of Medicine on 14th Street. The Manhattan Gas Light Company purchased land at the southeast corner of 15th Street and Irving Place in 1855, where it erected a Renaissance Revival office structure. Just south of the Gas Light Company's office was the Academy of Music, New York's third opera house, which opened in 1854. The structure burned down in 1866, destroying the blockfront on 14th Street between Third Avenue and Irving Place. The Academy of Music was rebuilt and continued to serve as an opera site until 1887, when it was turned into a movie theater. The Tammany Hall political organization purchased the former medical school site and built its headquarters building there. Another building on the present Consolidated Edison Building's site, a mansion at 2 Irving Place, served as headquarters for the Lotos Club. Construction Hardenbergh structure In the 1880s, at a time when competition between New York City's gas companies was high, the Manhattan Gas Light Company and several other gas companies combined to become the Consolidated Gas Company. By 1910, the original offices at 15th Street proved to be insufficient for the company's operations, and it had opened offices in several other buildings on the block, including the old Lotos Club house. As a result, Consolidated Gas hired Henry Janeway Hardenbergh to design a 12-story office building on that site. The building was to be erected in two phases so the company's operations could run with little interruption. The architect had previously constructed a showroom for the company. The first phase of construction, between January and September 1911, entailed building a building at 124-128 East 15th Street, which upon completion housed the company's subsidiaries and affiliates. The original headquarters and the Lotos Club house were originally retained as offices, but this soon proved to be insufficient as well. Consolidated Gas modified its plans to accommodate an additional seven stories, including a penthouse, in the new building, and acquired an area extending east from the existing property. To support the additional stories, a truss system was built to distribute the weight between the older structures and the newer building. Warren and Wetmore structure After the 19-story building was finished in 1914, Consolidated Gas rented out some of the additional space in the building, since at the time, the company did not need to use the entire floor area. A two-story building at 144 East 15th Street was added