Engineering of World War I.
The resulting Crater of a Lochnager Mine near La Boisselle France in the Somme Region.
Report by 2nd Lieutenant C.A. Lewis of 3 Squadron, flying a Morane Parasol.
"At Boisselle the earth heaved and flashed, a tremendous and magnificent column rose up in the sky. There was an ear-splitting roar drowning all the guns, flinging the machine sideways in the repercussing air. The earth column rose higher and higher to almost 4,000 feet (1,200 m). There it hung, or seemed to hang, for a moment in the air, like the silhouette of some great cypress tree, then fell away in a widening cone of dust and debris. A moment later came the second mine. Again the roar, the upflung machine, the strange gaunt silhouette invading the sky. Then the dust cleared and we saw the two white eyes of the craters. The barrage had lifted to the second-line trenches, the infantry were over the top, the attack had begun"
The Mine was detonated under the German front lines at the start of the Battle of the Somme. It covered 9 trench dugouts that could contain 9 officers and 315 men. The bodies of those killed were obliterated by the explosion, so a count of the dead is not possible.