The U.S.-led military coalition fighting ISIS has ruled out friendly fire as the cause of death for Gunnery Sgt. Scott Koppenhafer, a Marine Raider who was killed on Aug. 10 near an Iraqi island on which U.S. and Iraqi forces later dropped 80,000 pounds of munitions, officials confirmed.

Nancy Youssef of the Wall Street Journal revealed in August that investigators would look into whether Koppenhafer had accidentally been killed by U.S. or Iraqi troops.

On Tuesday, Shawn Snow of Marine Corps Times first reported that military officials had determined that Koppenhafer had not been killed by friendly fire.

Operation Inherent Resolve issued a statement on Tuesday confirming that Koppenhafer and a U.S. military contractor were killed “by enemy fire” near Qanoos Island, Iraq. Another service member was wounded during the battle.

“There is no evidence that suggests Iraqi Partner Forces engaged U.S. or coalition forces on this operation,” the statement says. “The deaths and injuries were incurred in the line of duty.”

A month after Koppenhafer was killed, U.S. and Iraqi aircraft flattened Qanoos Island, which the top U.S. military spokesman in Iraq described as “infested” with ISIS fighters. Air Force F-35 Joint Strike Fighters were involved with blitzing the island.

Originally from Colorado, Koppenhafer joined the Marine Corps in 2005, became a scout sniper, and became a critical skills operator in 2009 when he completed Marine Corps Forces Special Operations Command training as the Individual Training Course honor graduate, a MARSOC news release from August says.

He was meritoriously promoted to staff sergeant during his first of four MARSOC deployments and he was selected as MARSOC's 2018 Critical Skills Operator of the Year. His military awards include two Bronze Stars with “V” devices, two Combat Action Ribbons, and one Navy and Marine Corps Commendation Medal.