The demolition of the forts began on August 13. On that day, the heavy siege guns (two, it is believed), which the Germans had not intended to bring into action against Liége, entered the city and crawled through it to take up positions against the western forts. So affrighting were these engines of war that the German artillery did not attempt to operate them. They were handled by mechanics from the Krupp factory, the artillery officers merely working out the ranges. Prior to this time, such guns had never been dreamed of save in artillerists' nightmares. The weight of the great German siege gun is 71 tons. It is transported in four pieces, each part being dragged by three traction engines on caterpillar wheels, a thirteenth and larger engine going ahead to test the road and to assist each section in going up hills. The caliber of the gun is 16.4-inch (42-centimeter). The shell stands as high as a man's chin and weighs 1684 pounds. The percussion fuse is of mercury fulminate, which in its turn explodes nitro-glycerine, which explodes picric-acid powder, thus giving the bursting charge to the terrible force of an explosion of tri-nitro-toluol, one of the most destructive explosives known. About 280 pounds of this inconceivably powerful destructive is contained in the shell.[6] Nothing so terrible had ever before been seen in war as the effect of these great shells. Men were not simply killed and wounded, they were blackened, burnt, smashed into indistinguishable pulp of bone and flesh. When these engines of devastation arrived, General Leman knew that the end was near. Although severely wounded three days before, his spirit knew no thought of surrender. In Fort Loncin with a handful of men, he awaited the bombardment which could mean nothing but death. The fall of Fort Loncin was described by a German infantry officer who was attached to the Army of the Meuse. "General Leman's defense of Liége," he wrote admiringly, "combined all that is noble and all that is tragic. "As long as possible, he inspected the forts daily to see that everything was in order. By a piece of falling masonry, dislodged by our guns, both General Leman's legs were crushed. Undaunted, he visited the forts in an automobile. In the strong Fort Loncin, General Leman decided to hold his ground or die. "When the end was inevitable, the Belgians disabled the last three guns and exploded the supply of shells kept in readiness by the guns. Before this, General Leman destroyed all plans, maps and papers relating to the defenses. The food supplies also were destroyed. With about 100 men, General Leman attempted to retire to another fort, but we had cut off their retreat.