When the attack did come, the gun was able to get off one shot before the sheer number of Confederates made reloading impossible. Key, Robinson, and Cole used the various reloading tools as weapons, but when the crew was reduced to the three of them, they grabbed discarded muskets and retreated.
The trio were joined by Nathan Hunter and Aaron Fentis in a small group who sought desperately to fend off the attackers. To an extent, they were able to do so. But Cole saw that Confederate troops had gotten into the fort behind them. The group fled to the banks of the Mississippi River, where the found stores of ammunition placed on the river by Major William Bradford before the battle began in earnest. As the group began reloading their weapons, they saw Confederate troops were firing on the USS New Era, a ship that had been providing artillery cover during the battle, and was supposed to be covering the retreat of the garrison. Confederate sharpshooters were not letting the gunners open up their hatches. Finally, the New Era steamed up-river.
Things went from bad to worse for the group, as each were injured in turn, although none were fatally so. Key himself was shot in the arm, which broke the bone. Key and the rest of the group were evacuated to Mound City general hospital.