Two helicopters, one from the police and another from the army, flew over the plaza. Around 5:55 P.M. red flares were shot from the nearby S.R.E. (Mexican Ministry of Foreign Relations) tower. Around 6:15 P.M. another two flares were shot, this time from a helicopter (one was green and another one was red) as 5,000 soldiers, 200 tankettesCanal 6 de Julio, Tlatelolco: Las Claves de la Masacre and trucks surrounded the plaza. Much of what proceeded after the first shots were fired in the plaza remained ill-defined for decades after 1968. Records and information released by American and Mexican government sources since 2000 have enabled researchers to study the events and draw new conclusions.
