How did Colin Creevey die in 'Harry Potter and the Deathly Hallows'?

Colin was too young to fight in the final battle. Groups of the children had been escorted out of the castle to safety prior to all the Death Eaters arriving for the final battle. Colin, being stout-hearted and always idolizing Harry, snuck back into the castle to stand his ground in the fight. We don't know exactly what happened to Colin, but Neville and Oliver Wood found his body after everything was over.