On the morning of April 6, 1916, when headquarters learned of the German attack, supports and reserves of the Sixth Brigade were ordered forward. Two companies of the 29th were by this time with the 27th in the old British trenches and the new Canadian line beyond. The 28th occupied Voormezeele in the support center line. The 18th (Western Ontario) under Lieutenant Colonel Wigle, and 21st (Eastern Ontario) under Lieutenant Colonel Hughes, were in reserve at Dickebush. Two counterattacks were made simultaneously. Right-of-the-line bombers of the 27th and 29th headed an assault on Craters 2 and 3. Bombers of the 28th and 31st Battalions from the left center of the line were to occupy Craters 4 and 5. The troops of these two regiments had to come up from behind St.-Eloi and the Germans turned a heavy barrage of fire on them. They were unfamiliar with the ground, and seeing the outlines of two craters before them assumed these were their objectives. No one knew at the time that the craters on the left were in German hands. The attack on Craters 2 and 3 met with such a sweeping machine-gun fire from the Germans that the attack had to be abandoned.
Canadian artillery bombarded the craters during the day, and it was decided to attack 4 and 5 (supposed to be Craters 2 and 3) in the evening of April 6, 1916. Soon after dark fifty or sixty Germans, who had been hiding all day in shell holes, suddenly attacked the 31st, but were swept away by a heavy fire and only a few escaped.
Later in the evening the 28th moved forward in parties to the support of the much-tried 31st Battalion, making a junction with Major Daly (21st) behind the craters held by the Canadians. They were ordered to assault and capture Craters 2 and 3, but actually advanced against Craters 4 and 5. The bombers under Lieutenant V. P. Murphy, supported by Captain Styles, established themselves near the hostile craters, but owing to the darkness and impassable mud, and the ground a mass of holes, further progress could not be made.
Daybreak on the 7th found the Canadian infantry occupying Craters 6 and 7, but no progress had been made against German positions. The attackers had lost their way or were worn out from exhaustion. Though the opposing forces were within forty yards of each other during the night they had never come to grips.
Orders continued to come up from the rear to capture the enemy's intrenchments at any cost, and while reenforcements went forward, in the conditions existing at the front they mysteriously vanished.
That night the Fourth Brigade began to come up to the relief. The Sixth Brigade had fought nobly for three days and nights, with casualties of 617 officers and men. The 27th had lost eight officers and 209 of its rank and file killed or wounded. The 31st came next with 180 casualties, then the 29th with a roll of 180 casualties, while the 28th lost 101. The brigade had achieved a glorious defeat.
The relief, which lasted over four nights, put the 21st instead of the 27th on the right in the trenches, the 18th replacing the 28th in the center support position, while the 19th took the place of the 31st on the left in the Canadian craters.
Before the relief was completed on the night of April 8-9, 1916, a new attack was made against Craters 2 and 3. Captain Miller of the 21st, leading the attack on the right, was wounded in the engagement. With a bombing party he had gained the edge of Crater 2 without being observed. Finding the crater too strongly held, an attack was not attempted until Lieutenant Brownlee and fifty men reenforced the party. By this time the Germans were alert and started such a heavy fire that only a fourth of the party succeeded in struggling back to the trench.
The assault on Crater 3 by the 18th was also a failure. Lieutenant Kerr, who led the party, was wounded, and the blasting German gunfire forced them to reoccupy the old British line, putting out an advanced post before it fifty yards from the German crater. There was great difficulty in getting in the wounded. Captain McKeough and Sergeants Richardson, Cunningham, and Bowie again and again dashed through the fire to bring in the casualties. Meanwhile the 19th Battalion was engaged in relieving the 31st in the Canadian craters. Majors Moors and Morrison (19th Battalion), who successively held this dangerous position, could accomplish little as the German Crater 5 dominated it. Attacks were made, but all failed. On the night of April 9, 1916, an assault was pushed with some success. Lieutenant Davidson (21st) and Lieutenant Brownlee with a strong party of bombers seized Crater 1 and pushed north to capture Crater 2 from the rear. Here they failed, but dug in close to its rim and consolidated the ground thus won.
The 19th Battalion continued to hold positions in the Canadian craters until relieved on the 12th. Among conspicuous acts of bravery at this time was that of Corporal A. F. Lynch, who went out and dragged in a machine gun the entire crew of which had been killed.