Google's new location is only 20 miles inland. Not far at all when you consider that the elevation above sea level is only about 60 ft at that point.
During Hurricane Hugo, the US Navy misplaced one of their barges. It was found 1.5 miles inland, and had to be cut up on site because there was no way to get it back to the ocean. Also, the turntable bridge to the Isle of Palms was knocked off it's pivot, and took a couple of months to get it set back up on there. I was living in Charlotte at the time, and I was without power for a week.
In 1886, Charleston had a 7.1 earthquake that knocked down many of the buildings (roughly a third of the city was destroyed). There's a tectonic plate located to the east of the city that is moving westward. The area is considered to be overdue for another.
The new Cooper River bridge was designed for 300mph winds and a 7.4 earthquake (hopefully not at the same time!)