Silenced by Agony: B-29 Bomber Crew Tortured & Vivisected

by Jenny Chan

On May 5, 1945, a U.S. Army Air Forces B-29 Superfortress bomber from the 29th Bombardment Group (BG), based in Guam, embarked on a mission to bomb the Tachiarai airfield near Fukuoka, Japan. What began as a routine operation ended in tragedy, leaving an indelible mark on the history of World War II. The story of this ill-fated crew is one of unimaginable suffering, resilience, and unanswered questions—a stark reminder of the human cost of war.

The Mission and the Crash
Under the command of Aircraft Commander 1st Lt. Marvin Watkins, the B-29 crew took off with a clear objective: to strike a critical Japanese military target. Disaster struck after they were able to successfully complete their bombing run. The aircraft was hit by a Japanese fighter flown by Kinzou Kasuya, as they turned away from the target, igniting a fire in its number 4 engine and gas tank. With the situation rapidly deteriorating, the crew had no choice but to abandon the plane.[1]
All eleven men parachuted out before the aircraft exploded. While some landed near the crash site, others drifted farther away. Unbeknownst to them, their fates would diverge dramatically in the hours and days that followed.
Capture and Separation
One of the American airmen met a tragic end when the cords of his parachute were severed by a Japanese plane, causing him to plummet to his death. Another airman survived the descent but found himself surrounded by hostile villagers upon landing. Determined not to be captured, he fired all but one of his bullets at the approaching crowd before using the final round on himself. According to Toshio Kai, a high school teacher who has dedicated years to investigating the events described in Dr. Tono's book, two other airmen were quickly stabbed or shot to death shortly after reaching the ground.[2]
The remaining were captured by Japanese forces. Among them was 1st Lt. Marvin Watkins, the aircraft commander, who was separated from his crew and transported to Tokyo’s Kempei Tai headquarters for interrogation. There, he endured severe beatings, starvation, and deprivation of medical care. Watkins spent the remainder of the war in Horse Stall Cell 6 alongside 15 other American airmen, including notable prisoners such as Walter W. Dickerson, Frank G. Massey, Maynard B. Hanks, David G. Farquhar, Franklyn S. Green, and Walter W. Wiernick from the 6th Bombardment Group.[3]
For Watkins’ surviving crewmen, however, the outcome was far more sinister. They were taken to Kyushu Imperial University’s College of Medicine, where, under the custody of a military physician, they became victims of one of the most egregious war crimes of the Pacific Theater: vivisection.

Lieutenant Dale Plambeck

Map of Kyushu Imperial University

The Horrors of Vivisection
Teddy Ponczka was the first of the crew to be experimented on. The doctor took out one of his lungs to see if he could still breathe with a lung missing. Then they closed the wound shut. According to Dr. Tono, who witnessed the vivisection, Ponczka was under the impression that he was pushed into the operating room for help since he had a stabbing wound near his shoulder. The American was not expecting to be a part of human experimentation at Kyushu Imperial University. From there, Ponczka was tested from one experiment to the next. In one experiment, Ponczka was given intravenous injections of seawater to determine if it could replace saline. Ultimately, Ponczka bled to death. Then it came time for other Americans. Their lungs, livers, hearts, and other organs were removed to study the survival rate without organs. According to witnesses, the scientists kept the Americans alive to observe their responses. [4] 
These are crew members who were confirmed to be vivisected:

• Lieutenant William R. Fredericks (Co-Pilot)
• Lieutenant Dale Plambeck (Radar Navigator)
• Sergeant Teddy Ponczka (Flight Engineer)
• Corporal John Colehower (Gunner)
• Sergeant Czarnecki (Tail Gunner)
• Robert Williams (Radio Operator)

Their bodies were mutilated beyond recognition, and their remains were cremated by the staff members of the anatomy department. After the war, the Americans who were vivisected were listed as killed by the atomic bomb in Hiroshima, which was a ploy used by the Japanese military to cover up medical atrocities during the war.[5]


Marvin Watkins: The Sole Survivor
Captain Marvin Watkins stands as the sole survivor of the doomed mission. His captivity in the Omori POW Camp spared him from the horrors inflicted upon his comrades at Kyushu Imperial University. Despite enduring months of torture, starvation, and isolation, Watkins maintained his resolve and provided vital testimony after the war about the fate of his crewmates.
Upon liberation on August 29, 1945, Watkins returned to the United States, where he spent years searching for answers about what happened to his fellow airmen. Though he never received definitive confirmation, his account played a crucial role in exposing the atrocities committed by Japanese doctors and holding some perpetrators accountable during the Yokohama War Crimes Trials.[6]

This is the list of crew members and their fate:
Watkins (pilot) -- Taken to Tokyo, interrogated, and interned at Omori POW Camp. Released at end of war. 
Fredericks (co-pilot) -- Died during vivisection experiment
Shingledecker (bombardier) -- Place & means of death unknown
Kearns (navigator) -- Died in vicinity of crash site
Plambeck (radar navigator) -- Died during vivisection experiment 
Johnson (left gunner) -- Died in vicinity of crash site
Ponczka (engineer) -- Died during vivisection experiment
​Williams (radio operator) -- Died during vivisection experiment
Czarnecki (tail gunner) -- Died during vivisection experiment
Oeinck (right gunner) -- Died in vicinity of crash site
Colehower (nose gunner) -- Died during vivisection experiment

Justice Denied: The Postwar Trials
Immediately following the war, 996 Japanese war criminals from across the Pacific Theater were tried by the U.S. 8th Army at Yokohama. Of these, 854 defendants were convicted, including 124 receiving death sentences. However, only 51 of the death sentences were carried out. Among those executed was Lt. Sadamu Motokwa, the officer in charge of prisoner physical care at Tokyo Kempei Tai Headquarters, who was hanged for his crimes.
At Kyushu Imperial University, 30 doctors and military staff were tried for their roles in the vivisections and wrongful removal of body parts from the six airmen. Of these:

• 23 were convicted of vivisection and related atrocities.
• Lt. General Isamu Yokoyama, who commanded the medical experiments, along with two military officers and three doctors, were initially sentenced to death but later reprieved.
• Four others received life sentences. [7]​

Notably, Emperor Hirohito escaped prosecution entirely. General Douglas MacArthur, recognizing the Emperor’s symbolic importance in stabilizing postwar Japan, chose to shield him from accountability to minimize anti-American sentiment and facilitate Allied occupation and reconstruction efforts.
However, in 1949, President Harry Truman abruptly ended the war crimes trials, prioritizing Japan as a strategic ally against the spread of communism in Asia at the onset of the Cold War.[8] In 1952, President Eisenhower signed Executive Order 10613, allowing for the possibility of clemency or parole for those convicted of war crimes.[9]  By 1958, all Japanese war crimes prisoners had been paroled when MacArthur returned governmental authority to the Japanese.[10]

Sources:

1. Easton, Thomas. "A Quiet Honesty Records a World War II Atrocity." The Baltimore Sun, Tokyo Bureau of The Sun, 28 May 1995.
2. Ibid.

3. "B-29 POWs: Kempei Tai Atrocities." 6th Bomb Group , https://6thbombgroup.com/b-29-pows-kempei-tai-atrocities/ . Accessed April 20th, 2025
4. Roland, Charles G. "Human Vivisection: The Intoxication of Limitless Power in Wartime." Prisoners of War and their Captors in World War II, edited by Bob Moore and Kent Fedorowich, Berg, 1996, pp. 149-179.
5. "Airmen Killed by A-Bomb." Mansell.com, Mar 5, 1946, http://mansell.com/pow_resources/camplists/fukuoka/fuk_01_fukuoka/fukuoka_01/Airmen_killed_by_A-bomb_1946-03-05_A0118.pdf .
6. US Prisoners of War Subjected to Live Experiments During WWII, New Japanese Exhibit Shows." The Independent , 24 April 2015, https://www.independent.co.uk/news/world/asia/us-prisoners-of-war-subjected-to-live-experiments-during-wwii-new-japanese-exhibit-shows-10159183.html . Accessed April 20, 2025
7. "Japanese Admit Conducting Wartime Vivisection on Captured Americans at Kyushu Imperial University." The Sydney Morning Herald , 9 April 2015, https://www.smh.com.au/world/japanese-admit-conducting-wartime-vivisection-on-captured-americans-at-kyushu-imperial-university-20150409-1mh2i0.html . Accessed April 20, 2025
8. "Truman Doctrine, 1947." Office of the Historian, U.S. Department of State , https://history.state.gov/milestones/1945-1952/truman-doctrine . Accessed April 21, 2025
9. "Executive Order 10613: Amendment to Executive Order No. 10393." The American Presidency Project , University of California, Santa Barbara, https://www.presidency.ucsb.edu/documents/executive-order-10613-amendment-executive-order-no-10393-september-4-1952-establishing-the . Accessed Apr 21, 2025
10. https://history.state.gov/historicaldocuments/frus1958-60v18/d203