He believed at first that a magazine had exploded, but, as the dawn was rapidly advancing, he beheld in front of them, where Southern breastworks had stood, a vast pit two or three hundred feet long and more than thirty feet deep.

At the bottom of it, although they could not be seen through the smoke, lay the fragments of Confederate cannon and Confederate soldiers who had been blown to pieces.
"A mine breaking the rebel line!" cried Warner, "and our men are to charge through it!" Trumpets were already sounding their thrilling call, and blue masses, before the smoke had lifted, were rushing into the pit, intending to climb the far side and sever the Southern line.

But Colonel Winchester did not yet give the word to his own regiment, and Dick knew that they were to be held in reserve.
Into the great chasm went white troops and black troops, charging together, and then Dick suddenly cried in horror.

Those were veterans on the other side, and, recovering quickly from the surprise, they rushed forward their batteries and riflemen.

Mahone, a little, alert man, commanded them, and in an instant they deluged the pit, afterward famous under the name of "The Crater," with fire.