NEW : War on terrorism will continue , attorney general says . Rallies held in front of , against Islamic militants near ground zero . Americans remember the day when the planes crashed with solemn silence . The first 16 oak trees of more than 400 that will line the memorial have already been planted . At the closing ceremony , Obama makes a plea for religious tolerance .
NEW : War on terrorism will continue , attorney general says . Rallies held in front of , against Islamic militants near ground zero . Americans remember the day when the planes crashed with solemn silence . At the closing ceremony , Obama makes a plea for religious tolerance .