this is earlier today at arlington national cemetery. president obama laid a wreath at the tomb of the unknowns honoring those who fought and died for our freedom. and a dozen world war ii veterans laid right ted -- wreaths at the freedom wall. a half million americans died in that war. leland vittert is live at the memorial day parade in washington. >> reporter: could not be a more beautiful day out here for the parade along constitution avenue. this band from pennsylvania one of many that have doll down for the celebration there's 300,000 people i'm told lining this parade route. they have been here the past couple off hours getting ready. you've get a sense it's not only an observance and a celebration some enemy say they're so grateful their way to express that to those who made the ultimate sacrifice is to be here today, enjoy the parade and offer a moment of thanks.