Skip to main content
Related Content
  • Disasters and Phenomena
  • Operations
  • Intelligence
  • Theater of Operations--European
  • Cruises, Deployments, and Exercises
Document Type
  • Art
  • Historical Summary
Wars & Conflicts
  • Cold War
  • World War II 1939-1945
File Formats
  • Image (gif, jpg, tiff)
Location of Archival Materials
  • NHHC

H-Gram 029: Exercise Tiger Debacle, the "Deep Sea 129" Shootdown, and the USS Iowa Explosion

Attack on Slapton Sands
"Attack on Slapton Sands," painting, watercolor on paper, by Dwight C. Shepler, 1944 (88-199-DZ).


  • 75th Anniversary of World War II: Exercise Tiger, 28 April 1944
  • 50th Anniversary of the Loss of EC-121 “Deep Sea 129,” 15 April 1969
  • 30th Anniversary of the USS Iowa Turret Explosion, 19 April 1989

The poet T. S. Eliot wrote that “April is the cruelest month.” Although the next H-grams will be replete with U.S. Navy victories (Great Marianas Turkey Shoot, Battle of the Philippine Sea, Operation Neptune —the Normandy landings—and capture of U-505), it turned out that this one is a litany of disaster. This H-gram covers Exercise Tiger (the tragic rehearsal for the Utah Beach D-Day landings in 1944); the shootdown of EC-121 “Deep Sea 129” by North Korea in 1969 and other U.S. Navy aircraft losses during the Cold War; and the turret explosion on USS Iowa (BB-61) in 1989 and a history of previous U.S. Navy gun, ammunition. and powder accidents. If there is any moral/lesson learned to these, it’s that no matter peace or war (or in-between), training or operation, the Navy is always an inherently dangerous business. As a reminder, “back issue” H-grams may be found here.

75th Anniversary of World War II: Exercise Tiger, 28 April 1944

On 5 August 1944, Rear Admiral Don Pardee Moon shot himself in the head on board his flagship USS Bayfield (APA-33) in the Bay of Naples, Italy, leaving behind a suicide note. Secretary of the Navy James Forrestal announced that Moon’s death was the result of combat fatigue. Other reports indicate Moon suffered a serious head injury during darkened ship, resulting in constant severe headaches that impaired his judgement, which were described in Moon’s note. Others suggested the stress of planning for the rushed impending landings in southern France contributed to Moon’s decision to take his life. Yet others believed that a sense of guilt over what happened during Exercise Tiger, held in Britain that April—or at least concern that a court of inquiry might be convened— was a motivating factor.

Exercise Tiger was intended to be a full-dress rehearsal for the landings on Utah Beach, scheduled for June 1944 on the coast of Northern France. Instead, the rehearsal cost more lives (over 650) than the actual landings at Utah on D-day, 6 June 1944 (Omaha Beach was another story) and an example of what might have been on D-day had it not been for Adolf Hitler’s shortsighted navy policies, which left the Germans with a paltry naval capability to defend the Normandy beaches. Nevertheless, on the night of 27/28 April, nine German S-boats (Schnellboote—the Allies called them E-boats) got in among a convoy of eight fully loaded tank landing ships (LST) en route to the practice landing and hit three of them with torpedoes, sinking two (one going down in only six minutes) and blowing the stern off a third, with heavy loss of U.S. Army (at least 441) and U.S. Navy (198) life. There was no known damage suffered by the S-boats to Allied fire.

The LST convoy was part of a much larger “Assault Force U,” which was under the command of Rear Admiral Moon. Moon was an officer of stellar reputation, and the reality was that there is not much of anything he could have done that would have made a big difference in the outcome. Nevertheless, to preside over such a debacle weighed heavily on him. Other senior officers held him responsible, at least in an informal sense, and the fact that the first rehearsal landings were a succession of foul-ups didn’t help (including reported deaths by “friendly fire”). Moon, however, put those lessons to good use, and the actual landings on Utah Beach under his command were executed significantly better than on any of the other beaches, for which he is a hero, and his untimely death a tragedy as well.

That the actual D-Day landings didn’t suffer the same fate as Exercise Tiger was due to several factors. The principle one was Supreme Allied Commander General Dwight D. Eisenhower’s bold decision to launch the invasion in the face of adverse weather forecasts; the S-boats were in port when the Allied invasion fleet crossed the English Channel as the Germans assumed that no one in their right mind would invade in those conditions. Second, even if they had come out, there weren’t anywhere near enough S-boats to make more than a dent in the massive Allied invasion fleet. Third, the extraordinary Allied deception effort had the Germans, including what naval forces they had, expecting the invasion in the wrong place. For more on Exercise Tiger, please see attachment H-029-1.

50th Anniversary of the Loss of EC-121 “Deep Sea 129,” 15 April 1969

On 15 April 1969, four months after the release of the crew of USS Pueblo (AGER-2), the North Koreans celebrated dictator Kim Il-Song’s 57th birthday by deliberately shooting down a U.S. Navy EC-121M Warning Star four-engine intelligence collection aircraft well out in international airspace over the Sea of Japan, killing all 31 crewmen aboard. This was the largest loss of life in any U.S. aircraft shot down during the Cold War and the largest loss of life in any single U.S. Navy aircraft ever.

The EC-121, call sign “Deep Sea 129,” commanded by Lieutenant Commander James H. Overstreet, was downed by an AA-2 Atoll air-to-air missile fired by a North Korean MiG-21 Fishbed F fighter, which had flown a course timed to minimize time of flight to the EC-121, flying along a standard track that by then was well-known to the North Koreans. In a discussion the next day with the Soviet ambassador, the North Korean Deputy Foreign Minister stated that “they [the Americans] have not drawn the proper lessons from the incident with the Pueblo.” His statement was more true than he knew, because the shootdown of the EC-121 displayed much of the same convoluted command and control, ambiguous mission, national- and fleet-level confusion, slow crisis response, inadequate rapid operational response plan in the event of trouble, unreliable communications, and naïve belief that the North Koreans had any respect for international law that had characterized the capture of the Pueblo in January 1968. This time, however, it was the Nixon administration that had to grapple with the crisis response, but, like the Johnson administration before it, came up with much the same response: a massive show of naval force (four aircraft carriers, a battleship, and numerous other escorts) that steamed around furiously, but in the end did nothing.

Like the Pueblo, the EC-121 mission had been assessed as “minimal threat,” once again underestimating the audacity of the North Koreans. This assessment was reached despite the fact that North Korean Mig-17 fighters had badly shot up a U.S. Air Force ERB-47H over the Sea of Japan, 80 miles off the North Korean coast, on 27 April 1965, and despite significantly increased North Korean provocations along the Demilitarized Zone (DMZ) that had resulted in the deaths of 43 U.S. soldiers between 1967 and 1969. This wasn’t even the first U.S. Navy aircraft attacked by the North Koreans. On 16 July 1959, a P4M-1Q Mercator electronic intelligence collection flight was attacked and badly damaged by two North Korean Mig-15 jet fighters 40 miles off the North Korean coast, but made a successful emergency landing in Japan with a wounded tail gunner. However, by 1969, the lessons of 1959 had been long forgotten. In fact, during the early Cold War, U.S. Air Force and Navy intelligence collection and reconnaissance aircraft had been fired on over 40 times, mostly by the Soviet Union and People’s Republic of China, and at least 16 had been shot down. These losses included eight U.S. Navy aircraft (a PB4Y-2 Privateer—Navy version of B-24 four-engine bomber—four P-2V Neptune twin-engine ASW aircraft, a PBM-5 Mariner sea plane, a P4M-1Q Mercator ELINT collection aircraft, and an AD-5W Skyraider) with a total of 69 air crew lost.

The early Cold War was hotter than most people remember. A U.S. Navy fighter shot down a Soviet twin-engine A-20 torpedo bomber that approached too closely to U.S. Navy forces before the Inchon landings during the Korean War. At least four Soviet Mig-15 fighters were lost as a result of an overwater engagement with U.S. Navy carrier-based F9F Panther fighters in November 1952 (a future H-gram), and the tail gunner of one P2V Neptune also downed a Soviet Mig-15 that attacked the P2V near Vladivostok. For more on the EC-121 shootdown and a survey of U.S. Navy Cold War aerial engagements, please see attachments H-029-2 and H-029-3. For more on Pueblo, please see H-grams 014 and 025.

30th Anniversary of the USS Iowa Turret Explosion, 19 April 1989

On 19 April 1989, while conducting an exercise main battery gun shoot in the North Puerto Rico Operations Area, the re-commissioned World War II battleship USS Iowa (BB-61) suffered an explosion, followed by two more, in the center gun of her Number 2 16-inch gun turret that killed all 47 crewmen in the turret. The subsequent investigation would prove to be one of the most contentious and controversial in U.S. Navy history (regrettably, there are other contenders). The initial investigation conducted by Rear Admiral Richard Milligan was hampered by a failure to record and preserve evidence. It would also be grossly hampered by premature leaks of investigation information to the press by Navy officials. The investigation also identified numerous procedural, record-keeping, material, training, safety, and other deficiencies, to include unauthorized experimentation with different powder configurations for the guns, but could not identify any of these deficiencies as being the initial cause of the first blast. The blast instead was determined to probably be the deliberate suicidal act of the gun captain of the center gun. Although there were grounds for suspicion of the gun captain, there were also mitigating factors against this theory. Nevertheless, this conclusion would result in a public relations debacle, in which the Navy was accused by some family, press, public and Congress of scapegoating a dead sailor in a premature rush to judgement, and engaging in a cover-up of the serious deficiencies.

 As a result of public pressure, Congress directed that the Government Accounting Office (GAO) conduct an independent investigation, which it did with the aid of Sandia National Laboratory. Sandia experiments determined that it was possible that under certain circumstances that an “over-ram” of the powder could cause an explosion, but could not prove exactly how such an over-ram would have occurred. The Navy then conducted a second investigation that still could find no “accidental” cause for the explosion, but also conceded there was no proof it was “deliberate” either. After two years and 25 million dollars, the Chief of Naval Operations publically stated that the cause of the explosion could not be determined and issued a statement of regret to the family of the sailor initially accused. For more on the USS Iowa explosion, please see attachment H-029-4.

Besides the Iowa turret explosion in 1989, there have been multiple major turret and gun accidents aboard U.S. Navy ships during the course of history. These accidents include the heavy cruiser USS Newport News (CA-148) in 1972 off Vietnam with 20 killed; the heavy cruiser USS Saint Paul (CA-73) in 1952 off Korea with 30 killed; the battleship USS Mississippi (BB-41) in 1943 off Makin Island with 43 killed; the light cruiser USS Trenton (CL-11) in 1924 with 14 killed; the battleship USS Mississippi (BB-41) in 1924 off San Pedro, California, with 48 killed; the protected cruiser USS Charleston (Cruiser No. 22) in 1910 with eight killed; the battleship USS Misssouri (BB-11) in 1904 with 36 killed; the battleship USS Massachusetts (BB-2) in 1903 with nine killed; and the screw steamer USS Princeton in 1844 with only six killed, but that included the Secretary of the Navy and the Secretary of State.

In addition to turret explosions, other U.S. Navy ships and shore stations have suffered ammunition and powder explosions, a number of them catastrophic. These accidents aboard ship include the destroyer escort USS Solar (DE-221) in 1946 with seven killed; the transport USS Serpens (AK-97) obliterated off Guadalcanal in 1945, killing 255; the ammunition ship USS Mount Hood (AE-11) obliterated in Seeadler Harbor in 1944, killing 372 on multiple ships; the West Loch, Pearl Harbor, disaster in 1944 that destroyed six tank landing ships (LST) and killed more than 163; the destroyer USS Turner (DD-648) off New York City in 1944 that sank the ship and killed 138; the cargo ship SS Florence, with a 17-man U.S. Navy armed guard detachment aboard that exploded and sank in Quiberon Bay, France, in 1918, killing 41; the battleship USS Maine in Havana Harbor in 1898, sinking the ship and killing 266 (although this might have been due to hostile action); the cruiser USS Boston in 1892 at Mare Island, California, killing 15; and the steam-powered mobile battery USS Fulton in 1829 that killed 30.

Major U.S. Navy shore installation ammunition accidents included the massive explosion at Port Chicago, California, in 1944 that killed 320 (most of them African-American U.S. Navy stevedores) and led to the “Port Chicago Mutiny.” The other was an explosion, triggered by a lighting strike, at the Naval Ammunition Deport Dover, New Jersey, in 1926 that killed 19 people (that explosion was one of the largest non-nuclear explosions ever). For more on the history of U.S. Navy ordnance accidents please see attachment H-029-5.

Published: Fri Jan 24 17:09:24 EST 2020