Federal officials have called D.C. Mayor Adrian Fenty’s estimates of as many as 5 million attendees for Barack Obama’s inauguration an exaggeration in part because of their experience with massive crowds in the city before.

Veterans of major city events from agencies such as the Secret Service, Park Police and the FBI are expecting about 1 million people to descend on Washington. Fenty, though, has claimed that one in every 60 Americans may be in the District to see Obama on Jan. 20.