6th. Before Morning the Trenches were in such forwardness as to cover the Men from the enemys fire.1 The work was executed with so much secresy & dispatch that the enemy were, I believe, totally ignorant of our labor till the light of the Morning discovered it to them. Our loss on this occasion was extremely inconsiderable, not more than one Officer (french) & about 20 Men killed & Wounded—the Officer & 15 of which were on our left from the Corps of the Marqs. de St. Simond, who was betrayed by a deserter from the Huzzars that went in & gave notice of his approaching his parrallel.2
1. The trenches were opened between 500 and 600 yards from the British works, and the first parallel, supported by four redoubts (two on American ground, two on French), ran from the center of the enemy’s works to the York River (TILGHMAN  description begins Memoir of Lieut. Col. Tench Tilghman, Secretary and Aid to Washington, together with an Appendix, containing Revolutionary Journals and Letters, Hitherto Unpublished. 1876. Reprint. New York, 1971. description ends , 104). On the night of 6 Oct. the British concentrated their fire on a trench opened on the French left and on the redoubts on Pigeon Hill and the Hampton road and apparently were unaware of the work continuing on the first parallel during the night (CROMOT DU BOURG description begins [Marie François Joseph Maxime, Baron Cromot du Bourg]. “Diary of a French Officer, 1781.” Magazine of American History with Notes and Queries 4 (1880): 205–14, 293–308, 376–85, 441–52; 7 (1881): 283–95. description ends , 283).
2. Claude Anne Rouvroy, marquis de Saint Simon Montbleru (1743–1819), was in command of the 3,000 troops which de Grasse had transported from the West Indies. On the night of 6 Oct. he launched a diversionary attack against the British defenses on lower Yorktown Creek.