USS Cairo Strikes a Torpedo: December 12, 1862

Sketch by Rear Admiral Henry Walke of Cairo hitting the mine.  The image is incorrect in the
 respect that the mine exploded on Cairo's port side and not the starboard.

Early on the morning of December 11, 1862, Captain Henry Walke deployed two wooden gunboats, USS Marmora and Signal, to conduct a reconnaissance of the Yazoo River.  When both ships returned, their commanding officers reported that Confederate operatives had sewed numerous torpedoes (i.e. underwater mines) in the river.  The two men also informed Walke that they could sweep and clear the river if heavier ships provided cover fire against Confederate snipers hiding along its banks.  Walke agreed and assigned the ironclads USS Cairo and Pittsburgh and the ram Queen of the West to assist.  He gave strict orders that all ships were to stay out of the main channel of the river, as Marmora and Signal were to clear mines with small boats.  Bigger ships had to stay well behind during this process.

A sketch of one of the torpedoes/mines/"infernal machines,"
discovered by Ensign Fentress' mine clearing team. 
Part "C" contained the charge and Part "D" and "E" were
contact wires that set it off. 

The mine sweeping operation began early the next morning with Marmora and Signal leading the way.  At 11 a.m., watches aboard Marmora spotted a mine and proceed to render it inert.    After that, the story line becomes muddy.  Ensign Walter Fentress of Maromora later reported that his team was in the process of clearing the mine when he "heard an explosion from the Cairo, and on looking up I saw her anchor thrown up several feet into the air."

Lieutenant Commander Thomas Selfridge, late executive officer of USS Cumberland and now commanding officer of Cairo, reported that he believed Marmora was under attack by Confederate soldiers and rushed from the back of the squadron's formation to assist.  Upon discovering the gunfire was Marmora's crew attempting to blow up mines with gunfire, Selfridge ordered them to stop and Cairo would assist with small boats.  One minute later, "two sudden explosions in quick succession occurred." 

The ship slowly sank with no human causalities.  The ship's company transferred to 

Contemporary sketch of Cairo's
sailors sitting on the remains
of their ship. 

Queen of the West.  Twelve minutes after the explosion, Cairo sank beneath the surface and into the history books (she was the first armored warship sunk by an underwater mine).  After the ironclad sank, Selfridge ordered Pittsburg and Queen of the West to open fire on the woods along the river. Each ship fired about sixty shells into the woods and stopped.  There was no return fire and it is possible there were no Confederate troops present.  Meanwhile Maromora and Signal continued to sweep for mines and removed twenty before Selfridge ordered a retreat. 

Selfridge claimed that he believed that any part of the river Marmora passed through must have had no mines.  Thus, he ordered Cairo forward from the rear of the squadron's formation (against Walke's standing orders).  In his autobiography, What Finer Tradition, Selfridge only briefly mentions the incident.

U.S. Army Captain Edwin Sutherland, commanding officer of Queen of the West, provided insight into why Selfridge was so quick to have historians move along and ignore the incident. Sutherland reported to Walke that Cairo came along side Queen of the West and was asked why the ram stopped moving.  Sutherland replied that Marmora reported torpedoes ahead.  He then reported that not only did Cairo still go forward, but the ironclad entered the river's main channel (again, against Walke's standing order).

No charges or court-marital were ever filed against Selfridge.  In fact, Selfridge continued to have Porter's confidence and found Selfridge another ship to command (which he later ran aground).  The remains of Cairo can be seen in an outdoor exhibit as part of the National Park Service's Vicksburg National Military Park.

National Park Service photo of Cairo's remains