This video says about itself:
Mexico 7.1 Earthquake: ‘Absolutely Horrific Images’ | MSNBC
19 September 2017
NBC News‘ Steve Patterson reports on a powerful earthquake that struck just south of Mexico City.
From daily The Morning Star in Britain:
369 lives could have been saved in Mexico earthquake if building regulations were in line with other tremor hotspots
Wednesday 11th October 2017
NEARLY two thirds of the buildings that collapsed in last month’s Mexico earthquake were built using techniques banned in other seismic hotspots, US structural engineers revealed yesterday.
A Stanford University team said that some of the 369 lives lost could have been saved had the flat slab technique — in which floors are supported only by concrete columns — been banned after a 1985 quake.
“We have known for 30 years that this system killed lots of people, so why are we still using it?” asked Eduardo Miranda, a professor of civil and environmental engineering at Stanford.
“The right decision after ’85 would have been to completely ban this kind of construction. We could have saved lives.”
The team found that 61 per cent of the collapsed buildings were constructed with the design, which moves too much in an earthquake without reinforced concrete walls or lateral bracing to resist forces pushing structures sideways.
The columns, and connections between the slabs and columns, can easily break, prompting collapse, as was the case at a school where 26 people died, most of them children.
Experts said that Mexico’s post-’85 building regulations were relatively strong but said that corruption had allowed them to be weakened.
The regulations gave more responsibility to a network of private engineers who are hired and paid by developers and who submit structural plans to borough authorities.
It means private engineers — not government experts — vet projects’ structural safety, allowing developers already hostile to the more expensive rules to get around them.