During the First World War he was killed in action on the night of 24 April 1916 in Mesopotamia in an attempt to resupply the forces trapped in the Siege of Kut, at the age of 29.

He was posthumously awarded the Victoria Cross for his deeds, as was a fellow naval officer, Lieutenant Commander Charles Cowley R.N.V.R.

The General Officer Commanding, Indian Expeditionary Force "D", reported on this attempt in the following words:- " At 8 p.m. on April 24th, 1916, with a crew from the Royal Navy under Lieut.

At 1 a.m. on the 25th, Gen. Townshend reported that she had not arrived, and that at midnight a burst of heavy firing had been heard at Magasis, some 9 miles from Kut by river, which had suddenly ceased.

– the latter of whom throughout the campaign in Mesopotamia performed magnificent service in command of the "Mejidieh" – have been reported by the Turks to have been killed; the remainder of the gallant crew, including five wounded, are prisoners of war.

The account of the award is preceded by the following paragraph:- "The King has been graciously pleased to approve of the posthumous grant of the Victoria Cross to the undermentioned officers in recognition of their conspicuous gallantry in an attempt to re-provision the force besieged in Kut-el-Amara.In New Malden, Surrey, a plaque bearing his name was unveiled on the war memorial in April 2008, while Firman Close is named after him.