BAGHDAD, Iraq — Frequent deadly attacks by insurgents sapped morale and raised combat stress in a U.S. Army unit that included soldiers accused of raping and murdering a 14-year-old Iraqi girl, a private testified at a military hearing Tuesday. Pfc. Justin Cross recounted the "mentally draining" living conditions of the unit in the third day of the hearing to determine if five U.S. soldiers will be court-martialed in the March 12 assault near Mahmoudiya. The girl's parents and sister were also slain. "It drives you nuts. You feel like every step you might get blown up. You just hit a...