Reporting from MEXICO CITY — Even in one of the most earthquake-prone cities in the world, Peniley Ramirez never felt in danger inside her apartment. The seven-story building in the Roma neighborhood had survived the devastating Mexico City quake of 1985, which killed thousands.
“People said it was perfect during ’85, there was no damage at all, so we always felt safe,†she said.
But after Tuesday’s earthquake, neighbors had to break down her door with a pickax to get her out.
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The building was leaning and in danger of collapsing. Still, on Wednesday morning her husband and volunteers managed to retrieve paintings, toys, clothes and the television.
“I don’t know if I want to live in the Tower of Pisa,†said Ramirez, a reporter for Univision.
It was a widespread belief in Mexico City: If your house or apartment building was still standing after Sept. 19, 1985 — perhaps the most infamous date in the city’s modern history — it would withstand the next big quake. That theory was put to the test this week. It was wrong.
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Experts have long understood that history is an unreliable guide when it comes to how a building will fare in an earthquake, whether in Mexico, California or any other place criss-crossed by fault lines.
“This earthquake proved it: Doing well in one earthquake doesn’t mean you’ll do well in the next earthquake,†said Kit Miyamoto, a member of the California Seismic Safety Commission and chief executive of the structural engineering firm Miyamoto International. “Because every earthquake is different. And every building responds differently.â€
Although Tuesday’s magnitude 7.1 earthquake was far weaker than the magnitude 8 temblor of 1985, its epicenter was much closer to Mexico City — 80 miles away, compared with 250.
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That, experts said, largely explains the damage pattern emerging in preliminary reports: shorter, older buildings that were spared in 1985 were especially vulnerable this time, while taller buildings fared much better than they did a generation ago.
In videos taken during the earthquake and moments after, dust clouds hover over shorter, older buildings while taller ones sway violently but remain standing. The school south of downtown where at least 25 children were killed was three stories.
Rescue teams continue searching for students trapped in the rubble at Enrique Rebsamen school in Mexico City on Sept. 20, 2017.
(Gary Coronado / Los Angeles Times)
Why shorter and taller buildings can react differently in the same earthquake is a matter of physics — like a wineglass that shatters when subjected to the vibration of a particular musical note.
Mega-earthquakes, such as the one in 1985, are caused by extremely long faults. They produce low, booming shaking frequencies that can travel for vast distances — think of the bass beat you might hear from a distant rave — and produce the sensation of rolling motion, like the kind you might feel on a boat. Tall buildings are particularly vulnerable to this kind of motion.
That is particularly true in Mexico City, which sits on an ancient lake bed. Its soft soils amplify the shaking from an earthquake by 100 times, said Lucy Jones, a seismologist and former science advisor for risk reduction at the U.S. Geological Survey.
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Moreover, the lake bed is believed to have a natural resonant frequency that was activated in the 1985 earthquake and targets buildings that are between five and 20 stories — the very buildings that suffered the most damage in that disaster, which killed at least 4,200 people and by some estimates many more.
Something similar happened in the 2015 magnitude 7.8 Nepal earthquake, in which Katmandu, which also sits on an ancient lake bed, saw its tall buildings suffer damage, while its short buildings performed far better.
By contrast, short buildings are most vulnerable when they are close to the epicenter, which produces a shaking often described as herky-jerky, or having sudden, intense up-and-down or side-to-side movement. That high-frequency movement is not felt farther away from an earthquake’s source.
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The search continues for victims buried under the rubble of a fallen office building along Calle Alvaro Obregon in La Condesa neighborhood of Mexico City.
(Gary Coronado / Los Angeles Times)
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MEXICO CITY, -- SUNDAY, SEPTEMBER 24, 2017: People look for relatives and loved ones on a list posted where families set up tents to camp along Calle Alvaro Obregon as the search continues for victims buried under the rubble in La Condesa neighborhood in Mexico City, on Sept. 24, 2017. A powerful 7.1 earthquake rocked central Mexico on Tuesday, collapsing homes and bridges across hundreds of miles, killing at least 300 people. (Gary Coronado / Los Angeles Times) (Gary Coronado / Los Angeles Times)
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Susana Coronel Flores, whose nephew, Adrian Moreno, is missing in a collapsed building, sheds a tear as the search continues for victims buried under the rubble along Calle Alvaro Obregon in La Condesa neighborhood of Mexico City.
(Gary Coronado / Los Angeles Times)
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Residents stand in the street after the earthquake alarm sounded in Mexico City on Saturday morning before the shaking from a magnitude 6.1 aftershock in Oaxaca state reached the capital, causing buildings to sway.
(Natacha Pisarenko / Associated Press)
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Rescue teams stop their work Saturday after the earthquake alert sounded in Mexico City, four days after the powerful quake that hit central Mexico. There were no immediate reports of major new damage or casualties in the capital.
(Ronaldo Schemidt / AFP/Getty Images)
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Residents evacuate apartment buildings in the Tlatelolco neighborhood after an earthquake alert sounded in Mexico City on Saturday morning, four days after the powerful quake that hit central Mexico.
(AFP / Getty Images)
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Leodegaria Comonfort Ramirez, 49, whose home was destroyed in the recent quake, has a fractured shoulder and now shares a home with her neighbors in Jojutla. Her daughter was killed when the second story of the building they lived in came down on her head.
(Gary Coronado / Los Angeles Times)
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Margarita Martinez, left, shown with her children, sits where her home used to stand in the Mexican town of Jojutla, Morelos.
(Gary Coronado / Los Angeles Times)
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Maria Elena Jimenez Arizmendi, 81, sits outside her destroyed home in Jojutla with a few of her belongings packed into plastic bags.
(Gary Coronado / Los Angeles Times)
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Heróico Ayuntamiento, Jojutla’s local government office, suffered major structural damage in the recent earthquake.
(Gary Coronado / Los Angeles Times)
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Volunteers remove rubble alongside the Mexican military, beginning the reconstruction process where a block of homes in Jojutla was destroyed by the recent quake.
(Gary Coronado / Los Angeles Times)
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Maria de Pilar Paez Castillo, 69, receives medical attention outside a tent that she sleeps in near her damaged home in Jojutla.
(Gary Coronado / Los Angeles Times)
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Clara Velazquez Camargo, 77, right, tells her son Arturo Perez she would prefer to stay in a tent at a shelter at the La Perseverancia sport complex in Jojutla. “I want to live; I am afraid to return to my son’s home,†she said. The shelter is housing 350 people.
(Gary Coronado / Los Angeles Times)
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Neighbors place a tarp over part of the street near Leodegaria Comonfort Ramirez’s home, left, which was destroyed in the recent quake in Jojutla, killing Ramirez’s daughter.
(Gary Coronado / Los Angeles Times)
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The reconstruction process begins as residents discard their personal items damaged by the recent quake in Jojutla.
(Gary Coronado / Los Angeles Times)
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A worker repairs power lines next to Heróico Ayuntamiento, Jojutla’s local government office.
(Gary Coronado / Los Angeles Times)
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A crane removes a concrete stairway from a collapsed building in the Colonia neighborhood in Mexico City.
(Pedro Pardo / AFP/Getty Images)
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People pin notes and flowers to a sidewalk memorial at a park in front of one of a collapsed building in Mexico City.
(Luis Perez / AFP/Getty Images)
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Family members embrace as they wait for news of their relatives outside a quake-collapsed seven-story building in Mexico City’s Roma Norte neighborhood.
(Rebecca Blackwell / Associated Press)
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Japanese rescuers take part in the search for survivors at a flattened building in Mexico City three days after a strong quake hit central Mexico.
(Yuri Cortez / AFP/Getty Images)
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Soldiers and volunteers remove a car crushed by debris from a flattened building in Mexico City.
(Alfredo Estrella / AFP/Getty Images)
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Volunteer Elidia Marcos, 23, holds a sign asking for water, medicine and tools to aid victims of the earthquake in Mexico City.
(Gary Coronado / Los Angeles Times)
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Volunteer Fernando Gedeño, 20, carries wood to be used to support the structure of the collapsed Enrique Rebsamen school on Mexico City’s south side.
(Gary Coronado / Los Angeles Times)
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Refugio Gonzalez, 85, left, is comforted by volunteer Lety Rebollar, 19, of Mexico state, in a shelter holding 460 people displaced by the earthquake at Centro Deportivo Benito Juarez sports complex in Mexico City.
(Gary Coronado / Los Angeles Times)
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Rosalba Ramirez Vargas, center, and the prayer group “the Best Friends of Jesus†pray the rosary while anxiously waiting for news from rescue crews searching for children trapped in the rubble at Enrique Rebsamen school in Mexico City.
(Gary Coronado / Los Angeles Times)
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A rescue worker listens for signs of a person trapped under the rubble of a building felled by a 7.1 magnitude earthquake in Mexico City’s Ciudad Jardin neighborhood.
(Eduardo Verdugo / Associated Press)
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The Mexican Army load ruble into dump trucks while rescue teams work at night continuing to look for people trapped underneath a collapsed six story residential building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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Rescue teams working at night continue to look for people trapped underneath the ruble of a collapsed six story residential building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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The Mexican Army along side civilians load debris while search and rescue continues for people in a collapsed six story residential building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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Members of the Mexican Navy look on while a search and rescue team ooks for victims under the rubble at a collapsed building where five people were found dead in Colonia Roma in Mexico City.
(Gary Coronado / Los Angeles Times)
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Rescuers work at the top of a destroyed building in Mexico City trying to rescue a man two days after the magnitude 7.1 earthquake.
(Pedro Mera / Getty Images)
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A rescuer from Israel, center, takes part in the search for survivors in a flattened building in Mexico City two days after a strong quake hit central Mexico.
(YURI CORTEZ / AFP/Getty Images)
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Rescue services and volunteers raise their hands to ask for absolute silence during their search for victims under the debris of the school that collapsed in Mexico City.
(JOSE MENDEZ / EPA / Shutterstock)
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Mexico City residents scan the names of people who have been rescued and others who are still missing after the magnitude 7.1 earthquake.
(Pedro Pardo / AFP/Getty Images)
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An army of rescuers, firefighters, police, soldiers and volunteers search for survivors in a flattened building in Mexico City.
(Mario Vazquez / AFP/Getty Images)
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People who lost their homes in the earthquake rest inside a gymnasium turned in an evacuation center in Mexico City.
(Jorge Dan Lopez / EPA/Shutterstock)
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Rescuers search for survivors amid the rubble of a building flattened by the earthquake.
(Pedro Pardo / AFP/Getty Images)
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Volunteers await news as rescue teams look for people trapped beneath the rubble of a six-story residential building in Colonia Condesa, Mexico City.
(Gary Coronado / Los Angeles Times)
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Rescue teams use a blow torch on a slab of cement while looking for people trapped in the the rubble of a collapsed residential building in Mexico City Wednesday night.
(Gary Coronado / Los Angeles Times)
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People anxiously wait for news from rescue crews as the search continues for children trapped in the rubble of Enrique Rebsamen School in Mexico City.
(Gary Coronado / Los Angeles Times)
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Dairo Martinez, right, 15, looks for the name of his friend Reyna Davila, a student at Enrique Rebsamen School in Mexico City, on Sept. 20. The school collapsed in the 7.1 earthquake the day before.
(Gary Coronado / Los Angeles Times)
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A pair of heavily damaged churches are left partially standing in Jojutla, Morelos state, Mexico, following a 7.1 earthquake that killed more than 200 people.
(Rebecca Blackwell / Associated Press)
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The sky is exposed from inside the Santiago Apostol Church, which collapsed during Tuesday’s 7.1 earthquake in the town of Atzala in Puebla state, Mexico.
(Pablo Spencer / Associated Press)
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The Santiago Apostol Church in Atzala, in Puebla state, suffered major damage during Tuesday’s 7.1 earthquake in Mexico.
(Pablo Spencer / Associated Press)
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Rescue workers search for people trapped inside a collapsed building in the Del Valle area of Mexico City.
(Rebecca Blackwell / Associated Press)
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A survivor is pulled from the rubble from a flattened building in Mexico City.
(Pedro Pardo / AFP/Getty Images)
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An aerial view shows a flattened building in Mexico City. The search for survivors was continuing a day after a powerful quake hit the central part of the country.
(Mario Vazquez / AFP/Getty Images)
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Rescuers use a dog to search for survivors who may be buried under the rubble of a building flattened by a 7.1 earthquake in Mexico City.
(Diana Ulloa / AFP/Getty Images)
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Search and rescue teams continue to remove rubble and look for people in a collapsed six-story residential building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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Search and rescue teams remove rubble at a collapsed six-story residential building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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Rescue workers search for children trapped inside the collapsed Enrique Rebsamen school in Mexico City.
(Carlos Cisneros / Associated Press)
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Rescuers work at the Enrique Rebsamen school after a 7.1 magnitude earthquake shook Mexico City.
(EPA/Shutterstock )
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In this photo provided by Francisco Caballero Gout, shot through a window of the Torre Latina, dust rises over downtown Mexico City during a 7.1 earthquake Tuesday.
(Francisco Caballero Gout / Associated Press)
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Volunteers and rescue workers search for children trapped inside the Enrique Rebsamen school, collapsed by a powerful earthquake in Mexico City.
(Miguel Tovar / Associated Press)
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Alejandra Reynoso, left, and boyfriend Alejandro Gamez wait for news on Gamez’s sister Karen Nayeli, who is missing at a collapsed office building along Calle Alvaro Obregon in Mexico City.
(Gary Coronado / Los Angeles Times)
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People look for family and friends on a list of people rescued from an office building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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Search and rescue workers continue looking for people trapped in a collapsed six-story residential building in Colonia Condesa, in Mexico City.
(Gary Coronado / Los Angeles Times)
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A car crushed by debris from a damaged building after a quake rattled Mexico City.
(ALFREDO ESTRELLA / AFP/Getty Images)
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Rescuers, firefighters, police officers, soldiers and volunteers remove rubble and debris from a flattened building in search of survivors after a powerful quake in Mexico City.
(Yuri Cortez / AFP/Getty Images)
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An injured man is pulled out of a building that collapsed during an earthquake in the Roma Norte neighborhood of Mexico City.
(Rebecca Blackwell / Associated Press)
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People try to rescue survivors from a collapsed building in Mexico City on Tuesday.
People search for survivors in a collapsed building in the Roma neighborhood of Mexico City on Tuesday.
(Enric Marti / Associated Press)
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A construction worker searches a building that collapsed in Mexico City.
(Eduardo Verdugo / Associated Press)
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Rescuers and volunteers remove rubble from a collapsed building in search of survivors in Mexico City.
(Yuri Cortez / AFP / Getty Images)
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A car is crushed by debris from a building damaged in the 7.1 magnitude temblor.
(Alfredo Estrella / AFP/Getty Images)
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People in Mexico City remove debris after a building collapsed in a powerful earthquake on Tuesday.
(Alfredo Estrella / AFP/Getty Images)
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A security guard walks over debris of a collapsed building in the capital.
(Ronaldo Schemidt / AFP/Getty Images)
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People in Mexico City search a building that collapsed after a powerful earthquake centered southeast in neighboring Puebla state on Tuesday.
(Ronaldo Schemidt / AFP/Getty Images)
The 1985 quake therefore spared smaller buildings, many of them made of brick or brittle concrete that was long a staple of construction in Mexico, without much steel reinforcement that newer building codes require to protect against earthquakes.
This time the owners and occupants of some of those buildings were not so fortunate.
“The buildings that collapsed — most of them were very old buildings. Most of the buildings are maybe five, six stories,†said Guillermo Lozano, an aid worker with the humanitarian organization World Vision Mexico.
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“There’s a feeling that this city after 1985 was not vulnerable,†he said. “And that’s true in one way, because the new buildings, most of the new buildings were not affected. They’re OK. They had good protocols. People knew what to do. But what about the old buildings?â€
Keith Dannemiller, a freelance photographer who has lived in Mexico for decades, said he had long subscribed to the theory that pre-1985 structures were battle-tested.
But in recent years, he had started to wonder whether the smaller quakes that are common here were taking a toll on structures such as the six-story apartment building where he lives with his wife in the stylish — and aging — Condesa neighborhood.
Built in 1968, it suffered serious damage Tuesday, raining chunks of concrete and brick inside his apartment.
If the building proves uninhabitable, he said, he might look into renting an apartment constructed in the 1990s or later.
“Maybe the Condesa has lost a little glimmer and shine because of this,†he said.
Nearby in the Roma neighborhood, Mariana Dieguez, a 21-year-old dental student, stood outside a commercial building that had collapsed and killed a child on the sidewalk.
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“Most of the ones falling are older,†she said. “The ones built after ’85 have done well.â€
Constructed in the 1950s, the four-story building is now a mountain of concrete chunks and steel.
Dieguez had come to help in the rescue effort, joining a crowd of volunteers equipped with shovels, masks and gloves. But soldiers stationed there said it was too dangerous and turned them away, drawing angry shouts.
One of the volunteers, 25-year-old Ismael Alejandro Monroy Montesinos, explained why he had come to help: “This happened to our parents and now it’s happening to today’s generation.â€
Special correspondent Laura Tillman reported from Mexico City and Times staff writer Lin from San Francisco.
Rong-Gong Lin II is a Metro reporter based in San Francisco who specializes in covering statewide earthquake safety issues and the COVID-19 pandemic. The Bay Area native is a graduate of UC Berkeley and started at the Los Angeles Times in 2004.
