Updated:VINEYARD HAVEN, Mass.,None - Michelle Obama will join former first lady Laura Bush in ceremonies marking the ninth anniversary of the United Flight 93 crash in Pennsylvania during the Sept. 11 attacks.
Mrs. Bush had previously confirmed her participation, saying we "must never forget the brave sacrifice of these extraordinary men and women."
Passengers aboard the flight are believed to have struggled with its hijackers before the jet crashed in a field near Shanksville, Pa., killing all aboard.
Mrs. Obama's press office confirmed her role as the first lady vacationed with her family on Martha's Vineyard.
"Their show of support honors the lives and memories of these 40 heroes and everyone we lost on September 11th," said Neil Mulholland, head of the National Park Foundation. The group is helping build a memorial at the Shanksville site.
President Barack Obama continues to be criticized by families of those killed at ground zero on Sept. 11 for saying Muslims have a right to exercise their religious freedom, including at a planned mosque two blocks from the site.
United Flight 93 was traveling from Newark, N.J., to San Francisco when hijackers seized control. Forty passengers and crew were killed in the crash.
Construction on a permanent memorial to the victims is under way. Its first phase is expected to be dedicated in time for next year's 10th anniversary of the crash.