Unsk writes:

If memory serves, in the Mexico City quake in the 80’s, the epicenter was offshore off Acapulco, and quake was over 8.0. Acapulco was not severely damaged, but the new, thought to be well built steel frame high rises built over Mexico City’s filled in lake bed many, many miles inland, were. The harmonic frequency of the quake coincided with innate frequency of the steel moment frame high rises and the steel buildings as a result disintegrated. Older, poorly built multistory masonry structures stood with little damage right next to modern steel buildings that collapsed.

This is mostly true, although I know of no steel frame high rises that sustained serious damage (caveat: I don’t have hard data, just the results of a personal survey of downtown). Lots of buildings were concrete, and failed in one of two modes:

1) Floors shifted relative to each other, because the rebar in the posts was not adequately tied to the floors.

2) Concrete disintegrated. Many buildings collapsed into nothing but piles of dust and small chunks of concrete (fist size). I was told this was from using substandard concrete.

There was a clear resonance effect, with buildings around 10-12 stories high most commonly damaged.

See my link for pictures I took there – you can see the damage patterns, and other effects (such as the result of a seismic fountain popping through a brick sidewalk):

http://www.tinyvital.com/images/mexcity1985/index.html

BTW, experienced a 5.5 (or so) aftershock while there. I was in a residence up on a (rock) hill, and we felt nothing at all. We only knew we were in an aftershock because a member of the family was on the phone with someone in a non-rock area, who started shouting “Seismo!”. That aftershock that we didn’t feel killed folks just a few miles away, and the epicenter was 180 or so miles away (as described above)