In the early morning hours of September 19, 1985 an 8.0 magnitude earthquake occurred off the Pacific coast of Mexico. Coastal communities suffered relatively little damage and the quake did not produce any significant tsunamis. However, more than 200 miles to the east the sprawling metropolis of Mexico City, one of the largest cities on the planet, underwent horrific shaking that lasted for 5 minutes. During that time more than 400 buildings collapsed and thousands more were damaged. Millions of inhabitants lost water, electricity and phone service and worst of all an estimated 10,000 people lost their lives.

In the aftermath of the quake many were asking the same questions: how could such enormous devastation happen in a city that was so far from the quake's epicenter? And why were some parts of the city destroyed while other parts remained virtually untouched? The answers, it would turn out, lie in the nature of the land Mexico City itself is built upon. When the Spanish invaded Mexico in the 16th century they found a city perched on an island in the middle of an enormous swampy lake that lay between two volcanoes. Over the centuries as the city grew the lake/swamp was drained to provide land for expansion. As a result much of central Mexico City rests uneasily upon a mixture of volcanic clay, silt, sand and (relatively recent) lava deposits, while the outer regions are situated on much more dependable rock. The silty deposits that underpin much of the city center are perfectly tuned to the natural 'pitch' of seismic waves so when these waves arrived from the coast they found a perfect amplifier. Its not unlike an electrical signal from a guitar traveling quietly through a cable only to  burst out of the amplifier at ear splitting decibel levels.

In the aftermath of the quake the silence from the government was deafening. In fact it wasn't until 39 hours after the disaster that President de la Madrid addressed the situation publicly. With the government response virtually nonexistent the city's inhabitants took matters into their own hands and began scouring through the wreckage to find survivors. In all more than 4,000 people were pulled from the rubble alive and a large percentage of them owe their lives to these anonymous citizen heroes.

Ruins of the Hotel Regis, Mexico City Sept 19, 1985