Some computer games use multimedia presentations that are so realistic, they are used to simulate the real experience. Take Microsoft's Flight Simulator game, for example. It has been used in pilot training programs at flight schools. The game helps students learn how to conduct flight safety checks as well as how to operate navigational tools. A new edition of the game underwent alterations, however, after the terrorist attack on New York City's World Trade Center in 2001. Microsoft removed images of the WTC from its simulator game.