The US military says an American Marine has died in a non-combat related incident in Iraq. The announcement pushes the monthly American death toll to 21 as May draws to a close. That is the lowest since February 2004, when 20 troop deaths were recorded, according to an Associated Press tally based on military figures. The brief statement says the Multi-National Force - West Marine died Friday and the incident is under investigation. It does not give a location but the division operates west of Baghdad, primarily in the Anbar province.