I was in a 7.5 in Mexico City many years ago. My date and I were standing in the middle of the street holding each other so we wouldn’t be knocked down. The telephone poles and wires were lashing back and forth, but there was no other sound. Eerie, but plenty of motion, like a fast moving NY subway ride. When I got home, I was told the living room chandelier had been swaying back and forth touching the ceiling on one side and then hitting it on the other. The guy living upstairs was tossed out of bed. If this was a 7.5, I can imagine what a 7.8 might be like.
It’s curious to consider why some quakes are virtually silent, yet other of similar magnitude are very loud. One account of one of the New Madrid shocks indicates “The roar I thught would leave us deaf if we lived.”
The local geology of course makes big quakes in the US mid-south VERY bad. The entire account from above is here:
http://hsv.com/genlintr/newmadrd/accnt3.htm
Note the location: Louisville, about 200 miles away from the epicenter(s).