Three American service members have been killed during the US attacks on Iran, the military announced, marking the first American casualties in a major offensive that President Donald Trump said could lead to more losses.Three American service members have been killed during the US attacks on Iran, the military announced, marking the first American casualties in a major offensive that President Donald Trump said could lead to more losses. Three American service members have been killed during the US attacks on Iran, the military announced, marking the first American casualties in a major offensive that President Donald Trump said could lead to more losses.