Insurgents apparently shot down a US Army reconnaissance helicopter in this northern city, killing its two pilots, in the second fatal helicopter crash in Iraq in less than a week. One witness said he heard machine-gun fire before the helicopter crashed Friday, and children told soldiers that the sound of gunfire came from three or four directions and that the helicopter was flying erratically, possibly trying to evade it. The helicopter looked like it crashed on a muddy plateau and then cartwheeled down a 7.5-meter embankment that was sloped at about a 45-degree angle. It came to rest near strewn garbage. The helicopter's two pilots - the only people aboard -were killed. The pilot may have tried to land it in the dirt clearing, about six meters from some mud huts with clothes hanging along lines.