On the second day of the battle, Turner's brigade came under heavy attack, but was holding its position and repulsing the enemy despite losses from a second gas attack and heavy and accurate artillery fire. Alderson, believing that the Canadian division was capable of holding the line, ordered his brigade commanders to move reserves up to the front line to reinforce losses rather than withdraw. However, Turner made a sudden and unilateral decision to withdraw his brigade back to the General Headquarters (GHQ) line, several miles to the rear. Not only did Turner not inform Alderson, his commanding officer, of his decision, he also did not tell Brigadier General Arthur Currie, commanding the 2nd Brigade on Turner's right, that Currie's flank was now completely unprotected. (Currie would be forced to withdraw his brigade the next day, albeit in an orderly fashion, in order to avoid having his flank rolled up.) Turner's orders were also very dangerous to the well-being of his men – companies in the front line were in close contact with the enemy; when they left the relative safety of their trenches to retreat across hundreds of yards of open fields in broad daylight, the companies of the 3rd Brigade were subject to accurate and devastating small arms and artillery fire, and suffered grievous losses. This was exacerbated by the uncoordinated nature of the withdrawal – the orders arrived at various companies at different times, leaving each to withdraw as best it could, without the benefit of covering fire from other units. Some never received the withdrawal order, or the order arrived too late; they were flanked, surrounded and either captured or killed. Most devastating to the Allies, the 3rd Brigade's sudden withdrawal opened a 4,000-yard hole in their front line. Only the relative reticence of the Germans prevented an immediate catastrophe; having encountered stiff resistance from the Canadians the previous day, the Germans were not expecting a withdrawal, and were not positioned to immediately exploit the gap in the Allied front line the same day.