WASHINGTON -- America has lost its first soldier in its fight against Islamic State from non-combative wounds, the Pentagon announced on Friday night.19-year-old Lance Cpl. Sean P. Neal of Riverside, California, died Thursday in Baghdad. The incident is under investigation, the Pentagon said.Strikes against Islamic State in Syria began last month, after US President Barack Obama vowed to deny the group safe haven "anywhere they exist." Strikes against its assets began in Iraq a month prior.Operation Inherent Resolve has focused American air power on the defense of large population centers, including Erbil and Baghdad in Iraq, and Kobani on Syria's border with Turkey.Forty countries are part of the US-led coalition against Islamic State. The circumstances of Neal's death were not immediately available.Neal was assigned to 2nd Battalion, 7th Marine Regiment as part of a Marine task force.Reuters contributed to this report.