This attack had compromised surprise – and the attack on Mega was now commenced in all urgency. The 1st SA Irish (Col. Dobbs) were tasked to take the ridges east of Mega fort while the 3rd Transvaal Scottish (Lt-Col. Walter Kirby) were to occupy the a series of hills west of the fort and were to advance in line with the SA Irish. 2nd Brigade was to launch a direct attack on the fort and the Mega defensive complex. Despite incoming artillery fire, the Irish and Scottish regiments advances progressed well – but there was no sign of the 2nd Brigade who had not yet crossed the start-line, threatening to undermine the planned attack. At noon, a torrential rainstorm erupted and a thick mist enveloped the heights around Mega and it became obvious that the fort would not be taken by nightfall. The next morning, cloud and mist prevented air support and the Irish and Scottish battalions restarted their advance. It was only after the third day that the 2nd Brigade managed to reach their designated start-line due to poor navigation and the failure to identify serious terrain obstacles on their line of advance during reconnaissance. Clear skies on the third day permitted a coordinated attack with air support, artillery and the two brigades attacking together leading to an Italian surrender late that afternoon (18 February).