Look back at some of the work that went into building the memorial to United Flight 93 in Pennsylvania.
Tokens honoring Flight 93 sit near the fence surrounding the permanent memorial's construction site in May 2011.
April 15 is approaching. You may know how to fill out a basic tax return (or hand over the necessary paperwork to your accountant), but how much do you really know about doing taxes? Find some tax resources and test your knowledge here.