<p>Pfc. Daniel R. Parker, 18, thrown from a vehicle Tuesday, is the youngest 101st Airborne Division soldier to die in Iraq.</p>
<p>His name was Daniel Parker, but most everybody knew him as Dan.</p>
<p>Smiling Dan, 18, who a year ago raised his hand to solemnly swear that he would ''support and defend the Constitution of the United States against all enemies, foreign and domestic.''</p>