When university students in Mexico City protested the government 's actions around the time of the 1968 Summer Olympics , Díaz Ordaz oversaw the occupation of the National Autonomous University of Mexico and the arrest of several students , leading to the shooting of hundreds of unarmed protesters during the Tlatelolco massacre in Downtown Mexico City on 2 October 1968 . The Mexican army fired ruthlessly because a group called " Battalion Olympia " started the shooting between the unarmed students and many other people who let the students take shelter inside their homes . Statistics concerning the casualties of this incident vary , often for political reasons . Some people were kept imprisoned for several years . The crackdown would eventually be denounced by Díaz Ordaz 's successors , and ordinary Mexicans view the assault on unarmed students as an atrocity . The stain would remain on the PRI for many years
Tlatelolco massacre
Tlatelolco massacre
Gustavo Díaz Ordaz