What incidents ensured a Confederate loss at Chattanooga?

The Army of the Cumberland had nearly starved during the siege, and had had to be rescued by troops under Grant and Sherman, arriving from the West. These troops had done a lot of sneering at the Cumberlands, who suddenly lost their temper and stormed the heights of Chattanooga as a gesture of defiance.

The Confederates were completely taken by surprise, and sddenly the War in the West was over.