Updated at 3 p.m. ET
President Obama made an unannounced trip to Dover Air Force Base in Dover, Delaware, today to pay tribute to the 30 U.S. troops killed over the weekend in Afghanistan.
Two transport planes brought home the remains of the 30 servicemen, who were killed when their Chinook helicopter was shot down on Saturday. The crash was the deadliest single loss for U.S. forces in the decade-long war.
Mr. Obama paid his respects to the fallen servicemen on both C-17 transport planes and then spent about 70 minutes meeting informally with the troops' family members, offering his condolences for their loss and his deep gratitude for their sacrifice and service. About 250 family members and fellow servicemen and women of the fallen were at Dover for the ceremony.
Due to the catastrophic nature of the crash, the remains of the troops are still being identified. The Armed Forces Mortuary Affairs Office at Dover will make a positive identification through DNA, dental records and fingerprints.
"The crash they were in was so horrific and the state of remains such that there was no easy way to see this was this person or this was that person," said Van Williams, the public affairs chief for the Dover mortuary affairs office.
The casualties included 22 Navy SEALs, most of whom were members of SEAL Team 6 -- the counterterrorism unit that carried out the mission to find Osama Bin Laden. None of those involved in the Bin Laden raid were among the dead Saturday, U.S. officials have said.
CBS News Pentagon correspondent David Martin reports the SEALs aboard the helicopter were assigned to back up another team pinned in a firefight in the Tangi Valley, west of Kabul. The Chinook, which carried eight Afghans and one dog in addition to the 30 Americans, was apparently hit by a rocket-propelled grenade. An investigation is under way to determine the facts surrounding the incident.
Mr. Obama paid respect to the fallen troops inyesterday at the White House, saying they embody the best aspects of their country.
"We will press on, and we will succeed, but now is also a time to reflect on those we lost in the sacrifices of all who serve, as well as their families," he said. "These men and women put their lives on the line for the values that bind us together as a nation. They come from different places, and their backgrounds and beliefs reflect the rich diversity of America. But no matter what differences they might have as individuals, they serve this nation as a team. They meet their responsibilities together. And some of them, like the 30 Americans who were lost this weekend, give their lives for their country. Our responsibility is to make sure that their legacy is an America that reflects their courage, their commitment, and their sense of common purpose."
Defense Secretary Leon Panetta was also in attendance at Dover today, along with Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and his wife, Deborah; and Michael G. Vickers, undersecretary of defense for intelligence. Other military leaders were there as well.