Previous activity to lift the naval blockade at St Charles was narrated to the time USN Commander A H Kilty refused to allow Col Graham Fitch to assault the lower battery. Instead, Kilty dueled 20 year old Mississippian Francis Roby’s lower battery for 15 minutes and when finding his fire slackening, continued upstream with the ironclad St Louis trailing astern. The timberclads moved up while using the smoke rolling up above the timber for an aiming point to discharge their guns.
As the Mound City eased ahead, Captain John Dunnington waited until the iron behemoth was within point blank range of the lower 32-pounder. Soon the 175-foot long craft was in point blank range of both weapons. Like the lower battery there was no discernable target for Kilty to aim at.
At 10 o’clock a projectile from the upper 32-pounder unexpectedly tore through the armor and oak backing while killing three gunners before puncturing one (or more) of five 28-foot long boilers. Each was three feet across. Instantly the entire gun deck was filled with high pressure steam sending any number of burned crewmen leaping overboard.
Sailors on both sides were aghast to see the floating fort suddenly envelop with steam as it drifted helplessly down river. When it neared the lower battery, Captain Fry got no response to his demand for surrender. A section of Engineer Captain Andrew Williams report to General Hindman reveals the reprehensible conduct that followed: “When the explosion took place, the boat’s crew jumped into the water and into the boats to escape the scalding steam that was pouring out . . . . I immediately ordered all the sharpshooters who remained on the field, about 20 in number, to the river bank to shoot them.” Though Fry didn’t give the order, the onus of the misdeed would plague him and his family for the rest of their lives.
Col Fitch took the matter in hand and signaled the navy to cease firing and ordered his 600 Hoosiers to surge ahead with the reminder to “pay particular attention to the enemy who shot the seamen in the water.” When they reached the summit of the bluff, a fusillade caught Williams in the front and flank. Fry ordered him to fall back to Roby’s light guns, but when becoming hard pressed by the enraged enemy; they raced to Dunnington’s gun position 400 yards upriver. The retreat continued from there while the senior officers brought up the rear until their sailor’s legs at last carried them to some nearby woods.
The Confederates suffered a reported seven fatalities and 29 captured or wounded. A wounded Captain Fry was among the captured. Col Fitch claimed four slightly wounded.
As for the Mound City, only 25 of a crew of 175 men escaped uninjured or with slight burns. An avid researcher would be hard pressed to find another instance where a military unit suffered an 86% loss from one deadly shot. Commander Kilty was one of the burn victims even though he was in the pilot house forward of the vessel.
Williams was an engineer and had to know the temperature of pressurized steam was much hotter than say, the boiling temperature of water. He had to have known the sailors struggling in the water were driven by the instinct to survive and indicates as much in his report. He continued in service until captured at Arkansas Post six month later.
Boats moving Col Allison Nelson’s 10 TX Infantry to St Charles were hailed by an escaped remnant long after the action was over. The Texan’s had been delayed at DeValls Bluff from lack of ammunition.
The other tardy defense component was Captain Marion J Clay’s Cavalry Company sent from Little Rock on the 14th. When Hindman was directing the enrollment and organization of Arkansas’ who were subject to conscription, he directed no new companies were to be cavalry except by his specific authority. Clay’s mission was to observe and harass the naval expedition and report it’s movements to Hindman in a timely manner.
On the evening of the 17th, Hindman received a telegraphic dispatch from the AR River community of Southbend. Clay reported arriving when the action was over and quoted naval causalities relative to the loss of the Mound City. He closed by speculating the obstructions (sunken boats) probably would retard the enemy’s progress for a few hours.
Clay never got up close to see the disabled hulk, nor the lingering wisps of steam that indicated its demise. He got word from one of the 114-man scratch force defenders driven away by the plowboys from IN.
With the naval incursion temporarily arrested, two restful days were afforded the horsemen until the Union expedition nervously set out again. They were ambushed at every river bend within reach of the mounted men’s shotguns and rifles. The fleet commander turned back eight miles above Clarendon because the water was falling rapidly, causing the worrisome St Louis to scrape bottom on the way down. They waited at the mouth of the White for fresh instructions, returned briefly to St Charles, and then evacuated that place on the 25th to return to the point of origin.