Unidentified Man: Present, halt.</s>MELISSA BLOCK, Host: There in the 90-degree heat, the president paid tribute to America's fallen. Following Memorial Day tradition, he placed a wreath at the Tomb of the Unknowns.</s>MELISSA BLOCK, Host: There was a 21-gun salute.</s>MELISSA BLOCK, Host: And music by the United States Marine Band.</s>MELISSA BLOCK, Host: President Obama called his role as commander-in-chief his most solemn responsibility. And he said that responsibility carries a special weight on this day.</s>BARACK OBAMA: We remember that the blessings we enjoy as Americans came at a dear cost. That our very presence here today as free people in a free society bears testimony to their enduring legacy. Our nation owes a debt to its fallen heroes that we can never fully repay.</s>MELISSA BLOCK, Host: Of those fallen heroes, the president said, they gave of themselves until they had nothing more to give.
After President Obama formally announced the new picks for his national security team Monday, he left the White House and crossed the Potomac River to Arlington National Cemetery. In the 90 degree heat, paid tribute to America's fallen and following Memorial Day tradition, he placed a wreath at the Tomb of the Unknowns. He said his role as commander in chief is his most "solemn responsibility."