At 5:30 AM on 9 April 1917, four Canadian divisions, side-by-side, stormed Vimy Ridge. With incredible bravery and discipline, they overran the Germans along the entire front and continued pressing forward under heavy fire even when their officers were killed. There were countless acts of sacrifice as they charged machine-gun nests or forced the surrender of Germans in their trenches and dugouts. Hill 145, the highest and most important feature of the Ridge, and where the Vimy monument now stands, was captured in a frontal bayonet charge against machine-gun positions. After three more days of costly fighting, the ridge was in Canadian hands. The cost was heavy - 3,598 killed and 7,000 wounded.
The question we might ask is "what did the engineers do?" These articles help answer:
Message from the Governor General on the 107th anniversary of the Battle of Vimy Ridge**
The Science of War: Engineers and Geoscientists at Vimy Ridge
Gearing Up - Tunnels and Trenches
Trenches and Tunnels at Vimy Ridge
** The Governor General makes note of the 107th (Timber Wolf) Pioneer Battalion. one of Pioneer Battalions that were rolled into the Canadian Engineers during the First World War.