The 326th had its first encounter with the deadly mustard gas used by the Germans on September 12. They endured a night-long barrage of explosive and chemical artillery and persistent strafing by German aircraft. When the sun rose the next morning the soldiers looked out onto a contaminated wasteland. Although the attack on Saint-Mihiel was unsuccessful, the 326th Infantry held its ground and accomplished its mission. The regiment soon received replacements for the casualties sustained and trained in preparation for the next offensive.