After Cisterna
Cisterna marked the end of the 6615th as a complete regiment. The 4th Battalion was attached to the 504th Parachute Infantry Regiment (PIR) and then to the 1st Special Service Force. Colonels Darby and Dammer were given different assignments. Darby eventually became assistant division commander of the 10th Mountain Division and was killed by an artillery shell while he was riding in a jeep in northern Italy.
After the Battle of Cisterna, the 509th Infantry Battalion bore the brunt of a German counterattack. One of its companies was overrun, but the other companies fought valiantly and, with reinforcements from other regiments and divisions, was able to repulse the attack and took part in a parachute landing in Southern France. It ended the war with a very distinguished record.
Read more about this topic: 6615th Ranger Force