The memorial has had some unforeseen maintenance issues . In 1984 , cracks were detected in the granite and , as a result , two of the panels were temporarily removed in 1986 for study . More cracks were later discovered in 2010 . There are a number of hypotheses about the cause of the cracks , the most common being due to thermal cycling . In 1990 , the Vietnam Veterans Memorial Fund purchased several blank panels to use in case any were ever damaged ; these were placed into storage at Quantico Marine Base . Two of the blank panels were shattered by the 2011 Virginia earthquake
2011 Virginia earthquake
2011 Virginia earthquake
Vietnam Veterans Memorial