What happened in the Merrill Marauders do in their last mission? (Myitkyina, AUG 1944)

On their final mission to secure (mitch-in-aw) Myitkyina, the only all-weather airfield in the region, the Marauders suffered 272 killed, 955 wounded, and 980 evacuated for sickness. Merrill refused evacuation after a heart-attack before falling ill with malaria. By the time the airfield was secured, fewer than 200 Marauders were left out of the original 2,750 who had marched into Burma.