It was pitch dark at the time

TCD MS 10823 folio 1 recto

TCD MS 10823 folio 1 recto

[March 20th 1918] On the night of March 20/21st the Battalion was occupying the front line trenches near [Urvillers], a small ruined village a few miles south of St. Quentin. The front that we were holding was a wide one, nearly 2000 yards in width, and our posts were several hundred yards apart. The whole system of defence was arranged for rifle and machine gun fire, but without a thought of the possibility of a fog. After dinner on the night of March 20th I went all round  the front line inspecting the wire and looking at the various working parties. It was a beautiful moonlight night and scarcely a shot was fired on either side. It was so quiet that I remarked on the loudness of the German transport and on return to Battalion Headquarters about Midnight telephoned to the gunners to fire on to the roads from which the sounds seemed to be coming.
At 4.30.a.m. I was aroused by a sudden and terrific bombardment which appeared to have started all along the line and to extend as far as one could see and hear for a long way to the North and South. It was pitch dark at the time, with a thick fog, and quite impossible to see a yard in any direction. For two hours we kept up communication by telephone with the Battalions on the right and left, with our Companies and with Brigade Headquarters, but one by one the lines broke under the bombardment, till by