The ammunition became low, and to return for it was so dangerous that the general commanding did not like to order any one to fetch it, so called for a volunteer. Grant modestly says, "I volunteered to go back to the point we had started from.... My ride back was an exposed one. Before starting, I adjusted myself on the side of my horse furthest from the enemy, and with only one foot holding to the cantle of the saddle, and an arm over the neck of the horse exposed, I started at full run. It was only at street-crossings that my horse was under fire, but these I crossed at such a flying rate that generally I was past and under cover of the next block of houses before the enemy fired. I got out safely, without a scratch." When Monterey was conquered, and the garrison marched out as prisoners, young Grant was moved to pity, as he says in his Memoirs, thus showing a gentle nature, which he bore years later when thousands were falling around him, and he was still obliged to say, "Forward." After the capture of Vera Cruz and the surprise at Cerro Gordo, where three thousand Mexicans were made prisoners, the army advanced toward the City of Mexico. Between three and four miles from the city stood Molino del Rey, the "mill of the King," an old stone structure, one story high, flat-roofed, and several hundred feet long. Sandbags were laid along the roof, and good marksmen fought behind them. Near by was Chepultepec, three hundred feet high, fortified on the top and on its rocky sides. From the front, guns swept the approach to Molino. Yet, on the morning of September 8, the assault upon Molino was made, young Grant being among the foremost. The loss was severe, especially among commissioned officers.