On August 23, 2011 at 1:51 PM, a 5.8 magnitude earthquake shook the Washington D.C. region. The quake, whose epicenter was in Mineral, Virginia, was felt up and down the east coast of the North America from the Carolinas to Canada. The Smithsonian Institution buildings were evacuated and staff were allowed to reenter once inspections were done. The museums on the National Mall were shut down and all non-essential staff (across the federal government) were sent home for the remainder of the afternoon. In the aftermath of the earthquake, collections around the Smithsonian were deemed to be intact and secure. However, the Smithsonian Building or "Castle" and the Museum Support Center in Suitland, Maryland were closed the following day. The "Castle" completed in 1855, sustained cracks to its beams and possibly in the foundation. Plaster fell from the ceiling and other minor damages were incurred. All of the other Museum buildings and the National Zoo reopened to the public on August 24, 2011.