[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/11/10/art.bosalute1110.gi.jpg caption="The president saluted as he and the first lady deplaned from Air Force One and headed for Fort Hood on Tuesday."]
Fort Hood, Texas (CNN) - President Barack Obama joined top brass, thousands of rank-and-file troops and other dignitaries Tuesday to pay tribute to the 13 people killed in last week's massacre at the largest U.S. military installation.
Obama will be among the speakers at the Fort Hood memorial, which is scheduled for 1 p.m. (2 p.m. ET).
"The president will use the opportunity to honor 13 men and women who died, to talk a little bit about each of them and to discuss the contributions they made, and the notion that their memory lasts in the service and the dedication of the armed forces and that the people they touched, both in the military and outside," White House spokesman Robert Gibbs told reporters aboard Air Force One.
Defense Secretary Robert Gates, Army Chief of Staff Gen. George Casey, Texas Gov. Rick Perry and more than a dozen members of Congress are among those scheduled to attend the memorial.
Shortly before the ceremony and 1,200 miles away, the remains of one of the 12 soldiers killed in Thursday's slaughter were carried off a chartered jet in Milwaukee, Wisconsin.
An honor guard met the casket of Sgt. Amy Krueger on the apron at General Mitchell International Airport. Krueger, 29, was a high school athlete who joined the military after the September 11, 2001, attacks on New York and Washington, and was assigned to a medical unit that was doing checkups on soldiers bound for Afghanistan and Iraq when the shooting erupted, leaving 12 soldiers and a civilian dead and 42 wounded.
The suspected gunman in the attack is a 39-year-old Army psychiatrist, Maj. Nidal Malik Hasan. He was shot several times during the rampage and was in intensive care at Brooke Army Medical Center in San Antonio, Texas.
Hasan was removed from a ventilator over the weekend, but he has refused to speak to investigators and asked for a lawyer, senior federal investigative officials told reporters Monday.
No charges have been filed yet, and authorities have not identified a motive in Thursday's attack. But in a statement issued Monday night, the FBI said its investigation so far "indicates that the alleged gunman acted alone and was not part of a broader terrorist plot."
Hasan, a U.S.-born citizen of Palestinian descent, was a licensed psychiatrist who joined the Army in 1997. He was promoted to major in May and was scheduled to deploy to Afghanistan sometime soon, but had been telling his family since 2001 that he wanted to get out of the military.
He told his family that he had been taunted for his Muslim faith after the terrorist attacks of 2001. In August, he reported to police that his car was keyed - scratched - and a bumper sticker that read "Allah is Love" was torn off, leading to criminal mischief charges against a neighbor.
And in 2007, he argued during a medical seminar that Muslims in the Army should be allowed to claim "conscientious objector" status as the United States fought in Iraq and Afghanistan, the Washington Post reported Tuesday.
–CNN Correspondent Jill Dougherty contributed to this report.