The two cities attacked on 9/11 will play against each other in football on the 10th anniversary of the attacks.

The New York Giants will start their regular season by playing against the Washington Redskins in Washington on September 11, 2011. On that same day, 10 years ago, both cities were attacked by terrorist airplane hijackers. The World Trade Center in New York City and the Pentagon were targeted in suicide attacks that claimed the lives of thousands of people.
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Disclaimer: Yes, technically, the Redskins play in Maryland and the Pentagon is in Virginia, but that’s more of a technicality. They are both important icons in Washington D.C.