Looks like he had second thoughts and scribbled out the P.S. and wrote something else instead above it. I can't make it out.
A US Marine of the 1st Division writes the words 'Dark Horse' on a beam of the bridge western Fallujah, Iraq, where the bodies of two American contractors killed by militants were strung up in March, sparking the earlier U.S. siege, Sunday, Nov. 14, 2004. An earlier message left by soldiers reads: 'This is for the Americans of Blackwater that were murdered here in 2004, Semper Fidelis 3/5.'