Thomas is listed as being killed in action on 13 Apr 1918. The 3rd Battalion war diary entry for that day is transcribed below.

L’Epinette - In the Trenches – 13. 4.18: During night readjustment of line ordered but not completed by dawn owing to difficulties in communication. Heavy fog at day break. Enemy armoured car gave trouble by driving up to K.10.d.2.3 and using M.G. fire on our posts.

6.30am: Enemy attack developed on Centre and Left Coys, successfully repulsed on right but by ? of fog penetrated between left and centre Coys and gained L’Epinette Farm. Left Coy on the G.G [Grenadier Guards] at K.5.d. Gap of 400 yards at this moment between left Coy & D.C.L.I and SE of Arrewege which No 1 (30 men all told) attempted to fill. Nos 2 & 3 Coys left with flanks exposed & enemy working around them. These Coys held on until surrounded on three sides and then attempted to fight their way back. Very few succeeded.

Meanwhile left Coy heavily attacked by enemy at Le Cornet. This attack however was heavily repulsed.

2pm: Brigade front reported to be broken. 12^th K.O.Y.L.I having been forced to retire & enemy having penetrated our line to the left of the 4^th G.Gs the latter were then completely cut off. Our No 4 Coy being in same trench as 4^th G.G. were completely cut off. Bn HQ was moved to FM at Caudescure & this line was then established to run parallel with and E of the FM Beauleu – Arrewage Road.

At dusk remnants of Battalion (about 40 men) collected & held E & S of orchards at extreme SE of Arrewage.

Quiet night, rations and ammunition again brought up.

Casualties for day: Missing Capt Whitaker, Lt Russell, Capt Glover, 2^nd Lt Carr, 2/Lt ?, 2/Lt Leadbetter. Other Ranks K in A 17, wounded 84 Missing 259.

At daylight [14^th] Battalion withdrew to Borre, the 40 men remaining under the Command of O.C. Irish Guards until withdrawn at night.