A huge crater (and hole) was blown in the Confederate trenchworks surrounding Petersburg. Meanwhile, thousands of blue-clad Union soldiers had crept-up to the Confederate lines and were lying-down in strict military formation waiting for the explosion – and the signal to attack. The idea was to run into the gap and spread-out on both sides – killing and maiming the Confederate defenders until the area was taken. It is said that a number of high-ranking Union Field Officers were killed as the attack unfolded and that the Union-attack had to be led by the lower-level Field Officers who had no one directing the attack. Instead of running around the lip of the crater on both-sides – the Union men were led directly into the centre of the crater – and hit the steep and unclaimable wall at the other end. The Union soldiers became trapped and there was a sickening crush of bodies. Already the muddy water started to run red with blood!