David's surname is recorded as Dalzil by the Commonwealth War Graves Commission and, also, in regimental records. The correct spelling, Dalziel, is on the War Memorial and confirmed by the 1901 Census. He was named after his father who had died in 1898, aged 41. At the time of the Census, his family was living at 18 Priory Lane, Reddish. They originated from Scotland; his mother Jane and older brother, James, having been born there. They had moved to the Stockport area around 1884 and David and his three younger brothers, John, Robert and Charles had been born locally.
David's army service number is very low suggesting he might have been a regular soldier when War was broke out. If not, then he must have joined very soon after War was declared on 4 August 1915 and, after training, had joined the regular army's 2nd battalion as one of a draft of replacements for casualties from the early months of fighting.
On 24 April 1915, the Germans launched a large-scale attack against British forces, north of the Belgian town of Ypres (now Ieper). It involved the use of poison gas for the first time. There was fierce fighting for several days and the Allied line was pushed back towards the town, but was never broken. By the 28th, the German attack had been stopped. Over the coming days, the Germans continued to assault British positions.
The Regimental History records that, at noon on the 2nd, the Germans began an artillery bombardment of the area occupied by the Fusiliers but this ceased after a while and for a while the afternoon "was peaceful and gloriously fine".
"Then, soon after 4pm, came disaster. Just when many of "B" Company had begun to enjoy a drink of tea shouts went up, from several sentries to "look to the German trenches"..........Everybody looks and saw yellow clouds coming from jets put in the German lines, 3 or 4 every hundred yards, like water from a hose and shooting straight into the air. Then they settled down into thick billowing waves about three feet high......Their nature was recognised and as they took 2 - 3 minutes to cross No mans land it was possible to give a general gas alarm."
The men of "B" Company manned their trench and opened rapid fire. Private Bertenshaw fixed his machine gun in a tree stump and continued firing, even though he had no protection against the gas, towards the Germans he could see advancuing behind the gas. He continued to fire until he collapsed. Bertenshaw died the next day in hospital and is believed to have been recommended for a Victoria Cross (the Regimental History states it was awarded but there is no record of this). The German attack was broken up with help from British and French artillery.
After about 20 minutes the gas began to clear, but only about 30 men from "B" Company remained fit for duty. To their left, the other companies had been forced to withdraw to get away from the gas and had suffered many casualties.