NEW YORK - NBC News has swooped in and signed Richard Engel, a former freelancer who became one of ABC's most visible war correspondents when he stayed in Baghdad while other reporters left. Engel, 29, will begin reporting for NBC from Baghdad in early May, the network said Wednesday. In the days before the war, ABC, NBC and CBS all pulled reporters from Baghdad, concerned about their safety, and didn't send them back until American troops reached the Iraqi capital. Engel, a freelancer, decided to stay. Despite inexperience that occasionally manifested itself as boyish enthusiasm, Engel was used frequently on...