A classic accident waiting to happen

It comes as no surprise that Mexico City has been wrecked by a Richter 7.1 earthquake with an epicentre 75 miles away; the second really major quake in 2 months. The city is built on the bed of what used to be a vast Aztec lake and town complex close to the junction of two of the Earth’s tectonic plates. That sort of location; a dried up lake full of very soft soil; has been found to amplify the force of a quake by up to five times.