President Barack Obama traveled to Dover Air Force Base in Delaware today to attend the return of the bodies of 30 U.S. servicemen killed in a helicopter crash in Afghanistan on Saturday.

Obama had been scheduled to announce new fuel standards for trucks at an event in Virginia, but scrapped those plans; instead, four helicopters carrying the president, staff and reporters landed at Dover just after noon. The incident Saturday was the worst single-day toll for American forces in Afghanistan since U.S. troops entered the country nearly 10 years ago. It was one of largest tolls in a single incident of either the Afghan war or the fighting in Iraq.

The dead servicemen included 22 Navy SEALs, most of them 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.

The remains were returned to Dover in "unidentified" stautus until they are positively identified by the Armed Forces Mortuary Affairs Office. The Chinook helicopter crashed in the remote Tangi valley of Eastern Afghanistan. U.S. officials confirmed Monday that the servicemen were flying to the aid of American troops embroiled in a firefight when an insurgent shot down their helicopter with a rocket-propelled grenade.

The White House didn't announce Obama was going to the service until the helicopters landed. Col. Mark Camerer, the 436th Airlift Wing Commander, greeted Obama on the tarmac.

The event is closed to press and the traveling press with the president were ushered into a small auditorium to wait. The White House would not comment on reports that Obama was meeting with the families of the dead servicemen.