Trace Adkins will travel to Shanksville, Pa., to sing the national anthem at Friday morning's (Sept 11) service honoring the 40 people who died when United Airlines Flight 93 crashed on Sept. 11, 2001. Flight 93 was one of four commercial airliners hijacked in an attempt to strike targets on the ground. It was traveling from Newark, N.J., to San Francisco when it was diverted, but the hijackers crashed the plane after passengers tried to gain control of the cockpit before it could reach its intended target in Washington, D.C. Other hijacked planes struck the World Trade Center that day and killed 2,749 people. The keynote speaker at Friday's service will be retired U.S. Army Gen. Colin Powell, who served as secretary of state during the 9/11 attacks. Adkins and Toby Keith will perform a Friday night concert in Pittsburgh. ... In other news, Adkins will perform Sept. 25 as part of the Wounded Warrior Project's Soldier Ride in Nashville. Soldier Ride, which debuted in 2004, is the organization's rehabilitative cycling program for those injured while serving in the military. The segmented rides raise public awareness for those who have been injured while fighting overseas. Adkins will perform an acoustic set at the Loveless Barn during an event billed as Southern Shindig. The Soldier Ride takes place Sept. 26.