My wife was thinking that the aquifers in Palos Verdes have been depleted

and this likely is what is causing the collapse of Palos Verdes Drive South in Palos Verdes California, destroying many homes and roads. So, the likeliest thing that has happened is depleting the aquifers there made such a gap underground that everything is beginning to collapse into the Sea? 

There is also a potential problem eventually of the aquifers being depleted under Palm Springs too. So far, the aquifers have had enough water for all sorts of things to be built and done there but eventually all this will have to either change or more water is going to have to come from the Colorado River or something like this. Because the aquifers under Palm Springs likely are going to dry up too unless the next 20 years are really rainy years in the desert. And generally speaking rain in the desert is not very common.

Another I idea I had late the same night is that it could also have to do with oil being pumped out of the ground in the area too. This was thought to be the problem before when ground kept changing in the past.