Line 2 opened on August 1, 1970, in the stretch
Tasqueña–
Pino Suárez. Pino Suárez station became the first transfer station of the
Mexico City Metro, connecting with
Line 1, built one year before. On September 14, the line was expanded towards
Tacuba station. The last expansion of the line occurred in 1984 when two more stations were built:
Panteones and
Cuatro Caminos, the latter being the first station of the system to serve the
State of Mexico. Cuatro Caminos would remain as the only station to serve the suburbs of Mexico City until 1991, when
Line A opened and service reached the municipality of
Los Reyes La Paz, in the southeastern part of the State of Mexico with the stations
Los Reyes and
La Paz.
1975 train crash This line has seen the worst accident in Mexico City history when on October 20, 1975, when there was a crash between two trains at
Viaducto metro station. One train was parked at the station picking up passengers when it was hit by another train that did not stop in time. At least 27 people were killed and several wounded. After this accident, automatic traffic lights were installed in all lines. ==Chronology==