In the intrenchments facing Petersburg lay the 48th Pennsylvania Volunteers, largely composed of miners from the coal regions of that state. Late in June Colonel Pleasants of this regiment had submitted a plan whereby his men were to dig a tunnel to a point directly under one of the Confederate forts, plant a gunpowder mine there and blow a breach in the defenses through which troops could be poured and the town carried by assault. The scheme was plausible, provided the tunnel could be bored and Grant gave his consent, with the result that within a month an underground passage over 500 feet long was completed, a mine was planted with four tons of powder and elaborate preparations made for storming the Confederate works. Grant's orders were that all obstructions in front of the Union lines should be removed to enable the troops to charge the moment the explosion occurred, and that they should be rushed forward without delay until they were all within the Confederate lines. Accordingly, in the dead of night on July 29th, the assaulting columns were moved into position and when everything was in apparent readiness the signal was given to explode the mine. But though the match was applied no explosion occurred, and in the awful hush that followed Lieut. Jacob Douty and Sergeant Henry Rees volunteered to crawl into the tunnel and see what was wrong. To enter the passage at that moment was almost defying death, but the two men took their lives in their hands and, creeping in, discovered that the fuse had smoldered and gone out. They then relit it and made their escape just as a fearful explosion rent the air and great masses of earth, stones and timbers, intermingled with human bodies, leaped toward the sky. For a moment the waiting troops watched this terrifying spectacle and then, as the cloud of wreckage apparently swerved toward them threatening to descend and bury them beneath it, they fell back in great confusion and some time elapsed before order was restored and the charge begun. But Grant's orders to clear their path had not been obeyed, and the charging troops had to climb over their own breastworks, causing more delay and confusion. Finally, however, the leading brigades reached the great excavation torn by the mine, and there they halted awaiting further orders. But no orders came, for their terror-stricken commander had sought safety in a bomb-proof and when his hiding place was discovered the miserable cur merely mumbled something about "moving forward" and remained cowering in his refuge. Meanwhile, other regiments rushed forward, tumbling in upon one another, until the chasm was choked with men upon whom the Confederates began to pour shot, shell and canister. From that moment everything was lost and at last orders came from Grant to rescue the struggling mass of men from the awful death trap into which they had been plunged, but despite all exertions fully 4,000 were killed, wounded or captured.