of the Mexico City Metro was engineer Bernardo Quintana, who was in charge of the construction company Ingenieros Civiles y Asociados (Civil Engineers and Associates). He carried out a series of studies that resulted in a draft plan which would ultimately lead to the construction of the Mexico City Metro. This plan was shown to different authorities of Mexico City but it was not made official until 29 April 1967, when the Government Gazette ("Diario Oficial de la Federación") published the presidential decree that created a public decentralized organism, the Sistema de Transporte Colectivo, with the proposal to build, operate and run an underground rapid transit network as part of Mexico City's public transport system. The Mexico City Metro benefited from a great amount of technical assistance made available by France. RATP's engineering branch SOFRETU played a major role in its initial planning and the design of the first lines, hence the choice of tyre/rail technology. On 19 June 1967, at the crossroads of Chapultepec Avenue with Avenida Bucareli, the inauguration ceremony for the Mexico City Metro took place. Two years later, on 4 September 1969, an orange train made the inaugural trip between Zaragoza and Insurgentes stations, thus beginning daily operation up to today. First stage (1967–1972) The first stage of construction comprised the construction, done by Grupo ICA, and inauguration of lines 1, 2 and 3. This stage involved engineers, geologists, mechanics, civil engineers, chemists, hydraulic and sanitation workers, electricians, archaeologists, and biologists; specialists in ventilation, statistics, computation, and in traffic and transit; accountants, economists, lawyers, workers and laborers. Between 1,200 and 4,000 specialists and 48,000 workers participated, building at least of track per month, the fastest rate of construction ever for a subway. During this stage of construction workers uncovered two archaeological ruins, one Aztec idol, and the bones of a mammoth (on display at Talismán station). By the end of the first stage, namely on 10 June 1972, the STC Metro had 48 stations and a total length of : Line 1 ran from Observatorio to Zaragoza, Line 2 from Tacuba southwest to Tasqueña and line 3 from Tlatelolco to Hospital General in the south, providing quick access to the General Hospital of Mexico. Second stage (1977–1982) No further progress was reached during President Luis Echeverría's government, but during José López Portillo's administration, a second stage began. The Comisión Ejecutiva del Metro (Executive Technical Commission of