ROUGH CUT (NO REPORTER NARRATION)<br/> <br />President Barack Obama said on Thursday (July 17) the crash of a Malaysian jetliner on the border of Ukraine was a "terrible tragedy" and the United States would offer any assistance necessary to help determine what happened and why.<br/> <br />Obama said officials were looking into whether U.S. citizens were on board the plane. Malaysian Airlines confirmed that 23 U.S. citizens were among the passengers.<br/> <br />Obama made the comments at the beginning of remarks about infrastructure in Delaware.
