In April 1945, New England’s worst naval disaster of World War II took place just 5 miles off the coast of Cape Elizabeth, when a lone-wolf German U-boat arose from the murky depths of Casco Bay and fired one torpedo. Forty-nine men lost their lives, a great naval manhunt was launched and an enduring controversy lasting five decades had begun.

On June 26, 1944, the 200-foot-long, 25-year-old sub chaser, USS Eagle PE-56 — “a leftover from World War I” — entered Portland Harbor reporting for duty at the U.S. Frontier Naval Base. Eagle 56 was attached to the Brunswick Naval Air Station and assigned to patrol Portland Harbor and Casco Bay.

By the spring of 1945, though Germany was showing signs of imminent defeat, America’s military continued an all-out forward push, and Brunswick’s Naval Air Station continued to train new pilots and practice for deployment in Europe and the Pacific.

On Monday, April 23, 1945, squadrons of Hellcat and Avenger aircraft departed BNAS for exercises just off the shores of the Portland Headlight. The USS Eagle 56 was assigned to tow a green, floating target the men called a pickle. The pickle, a stand-in for an enemy submarine, was the target these pilots practiced bombing.

By noon, with exercises complete, the pilots turned their aircraft and headed back to Brunswick, leaving the USS Eagle 56 alone in Casco Bay. The 62-man crew of the Eagle 56 prepared the pickle for return to Portland Harbor, just as lunch was being prepared in the ship’s galley.

Suddenly, a massive explosion rocked the Eagle 56. The ship quickly broke into two sections, and the Eagle’s crew scrambled to survive. As survivors emerged from the broken hull of the Eagle 56 and swam through frigid waters — filled with black oil and flames — an odd site arose.

German U-boat U-853 briefly surfaced to witness their handy work as the men of the Eagle struggled to survive. After assuring themselves of victory, the U-853 suddenly slipped back below the waves.

Patrolling a few miles to the east where it witnessed a plume of water caused by the explosion was the United States Navy Destroyer USS Selfridge. The Selfridge swung about and arrived within minutes and began plucking 13 of the Eagle’s survivors and two of her dead from the briny sea. Forty-seven of Eagle’s crew went down with their ship.

As survivors were delivered to the Frontier Naval Base infirmary, a massive hunt for U-853 began as ships of the U.S. Navy and the U.S. Coast Guard began dropping depth charges in an attempt to blast the sub out of Casco Bay. But U-853 had slipped away.

By May 5, as Germany was negotiating its surrender, U-853 was sitting off the coast of Point Judith in Rhode Island when a new target appeared. The Merchant Collier S.S. Black Point, commanded by Maine Capt. Charles Prior, was loaded with coal bound for Boston. Suddenly, a torpedo from U-853 blasted through the Black Point’s stern. Of the 46 crewmen, 34 survived.

The U.S. Navy once again began pursuit of the submarine. Two Navy blimps from New Jersey and numerous Coast Guard ships joined 15 Navy warships in the search for U-853. For 17 hours, the hunt was relentless as hedgehog attacks and depth charge-runs were merciless.

By sunrise the next morning, the U-853 and all of her 55 officers and crewmen lay lifeless on the ocean floor. The S.S. Black Point and the USS Eagle 56 had been avenged.

A United States Naval Board of Inquiry investigating the loss of the Eagle 56 determined that a boiler explosion was responsible for the ship’s demise, effectively blaming the crew and denying benefits and recognition for the Eagle’s sacrifice.

In 2001, Massachusetts naval historian and attorney Paul Lawton had studied the loss the Eagle 56 and petitioned the Navy for reconsideration. Navy Secretary Gordon England agreed and reversed the Portland Board of Naval Inquiries findings, relisting the USS Eagle 56 as “lost due to enemy action.”

In 2018, divers searching for the Eagle 56 found the ship in two sections just off the coast of Cape Elizabeth. And both of the Eagle’s boilers were fully intact.

The sinking of the USS Eagle 56 was the worst naval disaster and loss of life in New England waters during World War II and the next-to-last U.S. warship sunk in the Battle of the Atlantic. Today, the loss of the USS Eagle PE-56 is remembered in the pages of American history and in the most enduring of our Stories from Maine.

Lori-Suzanne Dell is a Brunswick author and historian. She has published four books and runs the “Stories from Maine” Facebook page.