The F-15s began to leave Lambert on 15 August 2008, and by January 2009 most of the 13 remaining aircraft were in the main hangar being stripped of markings. The final two F-15Cs departed on 13 June 2009 after a closing ceremony titled "The End of an Era," which was attended by over 2,000 people. Some pilots had already begun B-2 training, while others chose to move to different units or retire early. The 131st Fighter Wing was the most experienced F-15 Fighter Wing in the United States; out of the four pilots that flew over 4,000 F-15 flight hours, three of them were from the unit.