Last night the Pentagon Memorial, which honors the lives of the 184 people who died when a hijacked airliner crashed into the Pentagon during the Sept. 11, 2001 attacks, officially opened to the public. The permanent outdoor memorial, which is made up of 184 benches, each with a name of a victim, will now be open 24 hours a day, seven days a week. DCist photographer Meaghan Gay and many of our Flickr contributors were there last night for the opening ceremony, and captured these images.