In wake of the 5.8 earthquake that rattled much of the East Coast, many analysts are now wondering if the region is prepared for a major earthquake.
Tuesday's quake prompted inspections of bridges, nuclear plants and many other structures from Georgia to Canada.
The Washington monument has been closed indefinitely after a crack 4 feet long and one inch wide was found in in the structure.
Many experts believe that the East Coast is due for a "big one," noting that there are major fault lines running from Canada to South Carolina.
And geologists say that the ground in the eastern U.S. transmits shockwaves better than in the West. Many large, older buildings couldn't handle a serious tremor.