In 1942, the battalion was redesignated the "1st Engineer Combat Battalion" and landed with the initial forces in the North Africa invasion. In 1943, the battalion cleared underwater obstacles and destroyed enemy pillboxes during the landings on Sicily. During the Normandy landings at Omaha Beach in 1944, the battalion led the assault forces, breaching gaps in the extensive enemy mine and wire obstacles and clearing the combat trails leading off the beaches.