A US helicopter crashed southwest of Baghdad on Tuesday, but first reports indicate the mishap was not due to hostile fire, the American military said. The crash occurred near Salman Pak on the southeastern outskirts of the Iraqi capital, a military statement said. The statement did not say whether anyone was killed or wounded, nor did it specify the type of helicopter. "An investigation will be conducted to determine the cause of the incident," the statement said. "However, initial reports indicate the crash was not the result of enemy fire."