The sound waves propagated into the urban space, across streets, parks and buildings, reaching the ears of the population and encouraging them to evacuate, to cover themselves, or to go to the closest safe point. It was the simulacro, a drill programmed for that specific day as a commemoration of the disastrous earthquake of 19 September 1985, a way to remember, practice, and create awareness of what to do in a similar event. In offices, schools, and hospitals, this yearly simulation is widely announced and prepared in advance. People follow the emergency protocols; most of them evacuate and, afterwards, return to their usual activities.
At 1:14 pm, an earthquake measuring 7.1 on the Richter scale hit the center and southwest territory of the country. The epicenter was located somewhere between the states of Puebla and Morelos, only 120 kilometers away from Mexico City. The proximity of the epicenter caused an 11 second delay of the alarm in the city , making it difficult or impossible for many to evacuate. Because of the drill earlier that day, there was also confusion about the authenticity of the emergency, as many witnesses recall, but the intensity of the tremors rapidly increased, making clear that this was a real earthquake. Around 38 buildings rapidly collapsed, either completely or partially, including offices, schools, and living spaces.
Dozens of spoken and written testimonials, videos, and images recorded at the instant of the earthquake reveal the pervading state of chaos, anguish, and emergency. In an urban context, an earthquake not only causes noises of crackling walls and pavement, falling buildings, and objects, it also provokes human sounds of anguish and excitement. My mother remembers the cathartic, high-pitched laughs of the construction workers at the top of an unfinished 24-story building just across the street, pretending they were on a roller coaster. My friend Tania wrote on Facebook how she was abandoned by a terrified eye-doctor inside a clinic; she had to find her way out without glasses, roaming across moving halls that began to crumble. Outside, on the Avenida Reforma, she saw a huge water tank falling down from a high rooftop and bursting on the ground. A TV announcer stuttered in the middle of his string of news, stood up and ran off under the lurching lamps that hung from the studio roof. On other TV shows, curses and cries went on air as crews left microphones and cameras on, replicating the alarm. Inside many schools, government buildings, and other public spaces across the city, dozens of cameras and phones recorded stomping feet, screams, and spoken instructions spoken intended to guide people to safety.
The earthquake lasted a little less than three minutes, measured from its beginning – with seismic waves flowing from the epicenter – to its end – with the final vibratory effects on city structures. During those minutes, urban noise is exacerbated, emanating with an exceptional, intensified quality proper to this particular natural disaster. The earthquake comes and goes, leaving a trace of alertness and trauma in those inhabiting the space. Soon, time opens up to a very different, post-disaster reality, saturated with new noises and movements, where inhabitants must cope with immediate changes, urgency of action, and material as well as human loses.