A unique feature of many Charleston, SC, buildings are earthquake bolts. After the devastating 1886 earthquake (estimated at 6.9-7.3 on the Richter Scale) many buildings regained structural integrity by the addition of iron rods through the building secured at the ends by Earthquake Bolts...
While hardly up to modern earthquake standards, these bolts have done their jobs for 143-years. Of course, Charleston has not experienced a major earthquake during that time