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NEWS | April 10, 2025

NAVSEA Remembers Crew of USS Thresher

By Team Submarine Public Affairs

Washington Navy Yard – Employees at Naval Sea Systems Command (NAVSEA) held a remembrance service honoring the crew of USS Thresher (SSN 593) on the 62nd anniversary of the deadliest submarine incident in U.S. history, April 10.

Attendees remembered the ship’s 129 crewmembers — 16 officers, 96 enlisted Sailors, and 17 civilian technicians — with a “two bell” ceremony. This Navy tradition honors the lives of fallen shipmates with a table set for their memory, a ringing of a ship’s bell and a moment of silence in respect.

“We all live our lives as best we can and hope that when it is our turn to pass into eternity, we will have made a difference in this world,” said keynote speaker Rear Adm. Todd Weeks, program executive officer, Strategic Submarines (PEO SSBN), during his remarks. “Their sacrifice changed everything in the submarine community. The passage of time tends to dim memories and blur recollections, but we have worked very hard to ensure that does not happen for the men of Thresher. Our memories of those valiant men and the challenges and changes their sacrifice brought about are alive and vibrant today, 62 years later.”

On April 9, 1963, Thresher, the lead nuclear-powered attack submarine of her class, sailed from Kittery, Maine, to approximately 220 miles east of Massachusetts to conduct deep-diving tests. After a rendezvous with Penguin-class submarine rescue ship USS Skylark (ASR 20), Thresher conducted trials throughout the day, before submerging overnight. The following morning, after reestablishing comms with Skylark, Thresher commenced deep-dive trials.

She dove slowly in a circular pattern beneath Skylark, maintaining communications, and stopping every 100 feet to check system integrity. But as Thresher approached her test depth, Skylark received an alarming, partial message. “… Minor difficulties. Have positive up-angle. Attempting to blow …” Another unclear communique was received which included the number “900.”

No other messages were transmitted. The Navy would eventually establish that Thresher and its crew were lost once the boat descended below crush depth, due to uncontrolled flooding, and imploded under the devastating pressures of the ocean.

In June 1963 the Navy established the Submarine Safety (SUBSAFE) program in response to this tragedy. SUBSAFE is a quality assurance program established by NAVSEA and designed to maintain the safety of the submarine fleet.

Stefanie Link, Executive Director for In-service Submarines, Program Executive Office Attack Submarines (PEO SSN), served as master of ceremonies for the remembrance and highlighted the duty owed to the crew of Thresher during her remarks.

“One of the hallmarks of our Submarine Safety program is pausing each year not only to honor those who died in the line of duty, but to keep their memory alive and to be mindful of the great responsibility we have at NAVSEA,” said Link. “We must continually uphold the standard, maintain a questioning attitude and speak loud enough to be heard if we see a problem.”

SUBSAFE certification is a necessary step in the development of new submarines. It occurs through all areas of design, material, fabrication, and testing. Records of the process are required to be maintained for the entire life of the submarine.

“Our SUBSAFE program has been very successful,” said Weeks. “It’s a disciplined process in which we certify that the ship is safe to go to sea. To certify means to guarantee as meeting a standard. The Navy uses a rigorous approach to certify that all new construction and overhauled submarines meet the standards of SUBSAFE. Since inception of the SUBSAFE program, no SUBSAFE certified submarine has ever been lost. All of us have played a part in the impressive safety record. All of us must continue to ensure the standard is not diminished or lowered over time.”

The Navy holds ceremonies annually to keep the memory of the Thresher and its crew alive. At NAVSEA, these remembrances serve as an opportunity to re-emphasize safety as a priority while paying respect to those we have lost.

“The sacrifice made by the fine Sailors and dedicated civilians of the Thresher resulted in changes and advancements that have made today’s undersea warfare safer and more effective,” said Weeks. “Their gifts to us are our attention to detail, focus on safety and humble pride in each successful submarine deployment. It is not enough merely to pay tribute to these men, for tributes, no matter how sincere, are only words. These men were members of a very special family. We too are members of that family, and we have a covenant with the men of Thresher to never let such a tragedy happen again.”

For more information on U.S. Navy submarines visit:

Attack Submarines (SSN)

Fleet Ballistic Missile Submarines (SSBN)

Guided Missile Submarines (SSGN)