coincidence or cause & effect?

A week ago, a gas company did a seismic survey along our road. They are mapping for fracking.* It shook our house like an earthquake from 50+yards away. Lots of rain since then. Yesterday, there was a mudslide including trees. We don't normally get mudslides in this area. Coincidence? or did the seismic shaking loosen the ground enough to make it happen? *For those who are not familiar, fracking or hydraulic fracturing, is basically giving the earth a high powered enema to release gas.