Earthquakes are a fact of life in California, they happen all the time. A century since the infamous quake of 1906 struck San Francisco, with a seemingly relentless sequence of deadly shakers that followed, Californians live with the knowledge that its only a matter of time before they’re hit again, and hit hard.

Today, in Los Angeles, California’s largest city and the second most populous in America, there lurks a sleeping geological monster of enormous proportions. Since 1999 a geological disturbance, known as the Puente Hills Thrust Fault, has been identified as a lethal contender. No one can say for sure when it could happen. Should it rupture into an earthquake, directly below downtown Los Angeles, scientists believe it could kill tens of thousands of people and cause hundreds of billions of dollars worth of destruction. That could make it America’s worst mega disaster.

Scientists are constantly studying two major aspects related to earthquakes. The first is the science behind the geology of southern Californian earthquakes. They are constantly devising new ways to study the faults below the surface that threaten residents. One method involves ground-shaking tests, in which trucks literally thump the earth, and the seismologists measure the waves. Much like an ultrasound, this process allows experts to actually ‘see’ faults hidden below the surface. Another technique is using satellites in earth orbit, combining GPS and radar technology to continually map the earth, and then over time track the changes and deformations in the earth’s crust.

The second major area of scientific endeavor related to earthquakes is within the science of engineering. Engineers at the San Diego University of California have constructed elaborate shake tables, in which structures as big as seven stories can be subjected to earthquake simulations, to see which kind of construction techniques can best withstand an actual earthquake if the Puente Hills Thrust Fault ruptures. 

If Los Angeles actually suffers a 7.5 magnitude earthquake that might result if the Puente Hills Fault were to rupture, how would the city respond? We’ll look into the various building codes and design of various types of structures throughout the city, including tall buildings, brick buildings, office buildings, hospitals, schools, stadiums and freeways and discuss their ability to withstand a large quake. We’ll also examine how well the emergency services could cope and explore the extent to which the public is prepared.

Finally, we’ll present viewers with a worst-case scenario, in which they’ll see the incredible damage and destruction, both economical and psychological, that would cripple one of the most important cities in the world. We’ll see buildings coming down, motorways coming apart and landmarks destroyed.