by M.C. Millman 

The USS Thresher was launched from Portsmouth Naval Yard in New Hampshire on July 9, 1960. The fast-attack atomic submarine was a new model with impressive improvements. 

The submarine was an accomplishment that was twelve years in the making. The Thresher could run more quickly and quietly, dive deeper than any previous models, and detect more than previous submarines could.

Less than three years later, on April 10, 1963, the USS Thresher sank in the Atlantic Ocean, taking the crew of 16 officers, 96  sailors, and 17 civilians down with it. 

On that fateful morning, the Thresher and the USS Skylark were conducting drills 300 miles off the coast of Cape Cod at 8 a.m. At 9:13 a.m., the Thresher contacted the USS Skylark via the underwater telephone to say that the submarine was experiencing minor problems.

"Experiencing minor difficulty…have a positive angle…attempting to blow…Will keep you informed," the Thresher shared. 

There was one more attempted communication, but it was indecipherable.

Five minutes later, sonar images showed the submarine plunging to the bottom of the ocean, breaking apart as it fell.

Later that day, an oil slick was discovered at the ocean's top. There were also pieces of cork bobbing in the water and heavy yellow plastic, all presumed to be from the sunken submarine. That night, the crew's families were notified that the Thresher was "Overdue and Presumed Missing".

Two days later, President John F. Kennedy ordered flags nationwide to fly at half-staff. 

It was later discovered that a leak in a silver-brazed joint in the engine room caused a short circuit that spread throughout the electrical systems. In the end, the equipment needed to bring the Thresher to the surface couldn't operate due to the electric problem.  

The horrifying disaster initiated fundamental improvements for subsequent submarines. Changes were made to their design, construction, inspections, safety checks, tests, and more, creating a much safer submarine force today.