The actual time of the attack is not known, but it probably occurred between 6.30 and 7 a.m., for at 7.10 a.m. a message was received from Lieut.-Col. Richardson (2/2nd Londons) that the enemy was in Jappy Keep, and about the same time the bombardment of the Battle Zone positions became still more intense. It must be borne in mind that fog hung over the whole area like a thick curtain, completely cutting off the Forward Zone from the observation, which it had been reasonably anticipated would be obtained over it. The Battle Zone troops and Brigade Headquarters were thus in the dark as to what was going on in the forward positions.
By 9 a.m. the enemy was reported in possession of Main Keep Locality, which meant a serious incursion into the defences on the vital flank. Steps were at once taken to employ the 3rd Londons (in reserve), one company being directed on Fargniers, while artillery and machine-gun barrages were laid on the Canal crossings at St Firmin and Beautor and on the area west of the captured positions.
Lieut.-Col. Dann now ordered forward patrols from each of the companies to endeavour to keep in touch with the situation, but it seems that if these orders ever reached the companies—they certainly were not received by the left company—the patrols themselves were destroyed by the enemy shell fire, for no information of value was obtained.
All this time no word had been received from the Travécy Locality though attempts were made to communicate from the 2/4th Londons and from the 18th Division on the left, and it is probable that the fog enabled the enemy to surround the garrison before its commander was able to communicate with his Headquarters.
During the morning Lieut.-Col. Richardson asked for counter-attack troops to be sent forward to him in the hope that the enemy in the St Firmin area might be ejected, but this request was refused by Division on the ground that the Battle Zone garrisons must be maintained intact. In consequence, therefore, of the extreme pressure on his front, Lieut.-Col. Richardson was compelled to order a withdrawal of the few remaining details of his shattered battalion on to the Fargniers area occupied by the 2/4th Londons, and by midday the fall of the Forward Zone was complete.
Shortly after midday the fog lifted slightly, and the 2/4th Londons in the Battle Zone became engaged with the enemy, who began to exert pressure on the extreme right flank. At about 2 p.m. the platoon of A Company holding Distillery Post next the Oise Canal was driven in and Lieut.-Col. Dann ordered the company of the 3rd Londons in Fargniers to launch a counter-attack. This effort was only partly successful, and Distillery Post remained in German hands.
About the same time the enemy advanced in large numbers all along the line, especially against the Farm Rouge and Triangle Localities. The former of these had always been regarded as a weak spot in the defences, and two reserve machine-guns were at once turned on to the enemy advancing against it. By 3.45 p.m., after a stubborn resistance against overwhelming numbers, Clarke's weak company was ejected from the Farm Rouge itself, and its grip on the remainder of the Locality much weakened. The assaulting columns continued to press on in the direction of the Quessy Locality, thus isolating the Fargniers position in the corner between the two Canals and completely cutting off Lester, who was still hanging on to his position in the Triangle against impossible odds.
A prompt endeavour to counter this very serious turn of events was taken by Brigade, who sent forward two platoons of the Suffolks to reinforce Clarke and fill the gap between him and Askham. The 3rd Londons also were drawn on again, and a second company was sent forward through Quessy to strengthen the Farm Rouge Locality. Of this company, however, only two platoons ever reached their objective, the others being destroyed by the enemy's fire at the crossing of the Crozat Canal.
At about 6.50 p.m. the Battle Zone, in spite of repeated and heavy enemy attacks, was still intact with the exceptions of the penetrations next the Canal on the extreme right and in the Farm Rouge Locality, and it was decided to lay down a provisional S.O.S. line on the forward edge of the Battle Zone. The enemy, however, was continuing his attacks with great persistence, and the gradual infiltration of his storm troops between our scattered positions was constantly altering the situation. By 7.15 p.m. he had already overrun the new S.O.S. line in the vicinity of the Distillery, and was beginning to close in on Fargniers from the south.