The original post in this thread stated that Mexico city was prone to earthquakes. The reason for this is well known, it is that it sits close to a tectonic plate boundary. So it is quite resonable for people responding to the OP, who know a bit about the subject, to "have a fixation on plate boundary tectonics". And then to say "we ain't talking about that", well yes we are, because the subject is earthquakes, and all of the most destructive and deadly earthquakes are related to plate boundary tectonics.