Scott had now 8,500 men and 68 guns. He moved, September 7, upon Molino del Rey (King's Mill), a group of stone buildings 500 yards long, forming the western side of the inclosure surrounding the rock and castle of Chapultepec, and 1,100 yards from the castle, which is a mile and a half from the city wall. Scott's purpose was to enter the city on the south, and he considered the castle of slight importance. He supposed that the battle of Molino would be a small affair. Worth anticipated a desperate struggle, and took up his position in the dark on the morning of the 8th. At 3 A.M. he opened fire with his twenty-four pounders, and his storming party advanced toward the point where the enemy's batteries had been, but their position had been changed, and they suddenly opened fire on the flank of his 500. After various contests, the fighting became a struggle for the possession of the Molino. A desperate and deadly fight took place. The southern gate gave way and the Americans passed in. The fight was renewed with bayonet and sword, and Worth lost a large number of the flower of his forces. At last the Mexicans, all but 700, retreated to Chapultepec. On the left the Americans were received with a murderous fire, which was long continued. Their whole artillery was then concentrated upon the Casa Mata and its works, which, after a desperate defence, were abandoned. Except as an outpost to Chapultepec, the position had no value. By Scott's order Worth withdrew his command, and left to the enemy the field which had been so dearly won. Of 3,500 Americans in the fight, 787 had fallen, including 59 officers. [Sidenote: Chapultepec] The Rock of Chapultepec rises 150 feet, and is crowned by the great castle. The northern side was inaccessible; the eastern and southern sides nearly so, and the southwestern and western could be scaled. A zigzag road on the southern side was swept by a battery at an angle. The crest was strongly fortified; ditches and strong walls and a redoubt were constructed at various points. The garrison numbered 2,000, and thirteen long guns were mounted. A select party under Captain Joseph Hooker seized the Molino, and at night Pellow threw his whole force into it. Two forces made a desperate assault on the intrenchments in front, united and passed the Mexicans and mounted the western slope. A party passed around the western front, which they scaled, and gained the parapet. Their comrades on the western side climbed the southern slope at the same time and joined the two. The whole castle was occupied. The Mexicans were dislodged and many prisoners were taken. [Sidenote: Fall of City of Mexico]