Valley of the Kings rains. There is currently little year-round rain in this part of Egypt, but there are occasional flash floods that hit the valley, dumping tons of debris into the open tombs. The quality of the rock in the Valley is inconsistent, ranging from finely-grained to coarse stone, the latter with the potential to be structurally unsound. The occasional layer of shale also caused construction and conservation difficulties, as this rock expands in the presence of water, forcing apart the stone surrounding it. It is thought that some tombs were altered in shape and size depending on the types of rock the
Victims of Terrorist Attack on the Pentagon Memorial at Arlington National Cemetery). The monument has not received much attention. A critic for "The Washington Times", however, approvingly called it a "five-sided Rock of Ages". Paul Goldberger, architecture critic for "The New Yorker" magazine, was more cautious. By inscribing the name of each victim, he said, the memorial risks becoming a private monument rather than a monument belonging to the entire nation or a symbol of something larger than an individual person. On June 20, 2014, a man committed suicide by shooting himself near the Victims of Terrorist Attack on the Pentagon Memorial. Dozens of police vehicles from the