Writing to BusinessLine, Brian Tucker, President of California-based GeoHazards International, recounted a first-hand experience from the stricken city.
GeoHazards works around the world to reduce preventable death and suffering from natural disasters. This was the second time that Mexico had come face-to-face with massive temblors in recent times.
Earlier when the quake struck, Janise Rodgers, COO, GeoHazards, had given an invited presentation at a forum of the Mexican Society of Earthquake Engineering.
The sirens went off at 11 a.m. local time for a ‘simulacro’ (earthquake drill) planned to mark the anniversary of the devastating 1985 Michoacan earthquake.
At the national university UNAM, attendees at the earthquake anniversary forum calmly walked outside through wide, clearly marked exits.
The exit doors had safety features that are so often lacking in areas of the world where GeoHazards International works, said Rodgers.
The door was painted red, opened outward, had panic bars so they could be opened quickly, and were kept unlocked.
Real thing follows
Once outside, some people continued across the street to avoid standing underneath powerlines, as is the practice during the drill.
Police assisting with the ‘simulacro’ took photos. The team headed back inside after the all-clear and resumed. Then the real thing happened, Tucker quoted Rodgers as saying.
About two hours later, the presenting speaker stopped mid-sentence as sirens went off again, accompanied immediately by noticeable shaking.
In Mexico City, ‘go outside’ is what one is told to do during shaking, so the entire team went outside again – quickly this time. The shaking grew stronger then subsided soon after the team was out.
The team had just practiced, so there was no hesitation, no questioning where to go or what to do. Power poles were swaying back and forth; fewer people stood under them this time.
People poured into the street. Cars stopped. Everyone was on the phone trying to reach loved ones. For some minutes the networks were overloaded like one always hears about in earthquake scenarios.
Confirms worst fears
UNAM is in a hilly part of the city, away from the soft lakebed sediments that so amplified shaking in 1985.
Local engineers at the forum quickly expressed concerns that the shaking would have been much stronger on the lakebed part of the city.
Reports of building collapse trickled in, confirming their fears. Videos showing the collapse of concrete and masonry buildings were circulating on social media an hour after the earthquake.
The building where the safety drill was being conducted was quickly inspected and found to be undamaged, so the team went back inside.
Despite the modest shaking, windows had broken on the building next door, demonstrating the vulnerability of older exterior cladding systems.
The forum carried on, though the presenter had the unenviable task of talking with sirens still going off outside.
Local engineers continued to receive damage reports throughout the afternoon. Most distressing was the collapse of the Colegio Enrique Rebsamen elementary school, where at least 21 students were killed, according to last reports, and more were feared trapped under the rubble.
New schools in the city are designed to be earthquake resistant, but, as in many places, a stock of existing vulnerable buildings needs to be addressed.
“Our hearts go out to those recovering from this major earthquake and its impacts, which are just coming to light,” said Rodgers.
Information Source: The Hindu Business Line