By May 1944, the US had equipped four airbases near Kharagpur, India with 130 of America’s newest and largest bombers, the B-29 Superfortress. Each plane had a crew of eleven men and many more men were on duty to provide ground support for the complex aircraft. The Superfortresses were designed, built and deployed to conduct long-range, high-altitude attacks on the Japanese home islands. From design to deployment, they cost the equivalent of $45 billion in today’s US dollars, making them the single most expensive project of the entire war. The four B-29 airbases in India were Chakulia, Charra, Piardoba and Kalaikunda. The planes at Charra moved later to Dudhkundi.

On June 5, 1944, B-29s from these bases began “Operation Matterhorn” which included the first bombing attacks on the Japanese homeland since the Doolittle raid 26 months earlier. The attacks were a logistic nightmare. Before each bombing mission over Japan, C-46 and C-47 cargo planes and the B-29s themselves had to make several flights over the Himalayas to forward bases in China, positioning fuel, bombs and spare aircraft parts for the final assault. The hastily built, high-tech B-29s also had unresolved problems of their own. Engine failures, in particular, caused more crashes than enemy fighters or antiaircraft guns. In addition to the attacks on the Japanese homeland, B-29s from the Indian bases conducted bombing missions against Japanese targets in Burma, Thailand, Vietnam, Sumatra, Formosa, Singapore and Manchuria.

The US military in WWII was segregated by race. All B-29 aircrews and the great majority of ground personnel at the B-29 bases were white. The 769th Chemical Depot Company at Kalaikunda, however, was an exception. As was typical for “colored” units at the time, most or all of the commissioned officers in the 769th were white while all the non-commissioned officers and other enlisted men were African American. One section of the 769th was responsible for handling napalm-filled incendiary bombs and these bombs were used frequently. The other section consisted of “toxic gas handlers,” responsible for bombs filled with mustard agent, cyanogen chloride and other poisonous gases. Although their toxic chemical bombs were never used, soldiers of the 769th kept a stockpile ready to be loaded onto the B-29s. If the Japanese had initiated chemical warfare, the US was prepared to respond immediately.

Maintaining toxic chemical bombs was neither easy nor safe, and the need to wear gas masks and protective clothing in India’s heat and humidity made the work particularly unpleasant. A mainstay of the US chemical arsenal was the 100-pound M47A2 mustard bomb, a bomb that proved particularly prone to leakage. In February 1945, for example, soldiers of the 769th found 2 leaking bombs which they were unable to repair. They transported the leakers by truck to Chakulia Airbase for burial.

By March 1945, intense fighting in the Pacific had allowed the US to establish bases in the Mariana Islands. These new bases were closer to Japan and easier to supply from Hawaii and the US west coast. The last of the B-29s were transferred from India to the Marianas, and the US began to reduce its stockpile of chemical weapons in India. As part of this reduction, soldiers of the 769th Chemical Depot Company were assigned to help transport 800 mustard-filled M47A2 bombs from Chakulia Airbase back to the central chemical depot at Ondal. During transport by truck from the Chakulia’s “toxic gas yard” to a rail siding, many of the bombs were found to be leaking. These leaking bombs were buried at Chakulia, rather than being shipped back to Ondal.

In April 1945, the depot at Ondal held at least 75,000 toxic chemical bombs which were considered surplus. The unneeded chemical munitions were scheduled to be shipped by rail to Calcutta, then transferred to two Liberty ships (the USS George B Porter and the USS OB Martin) for dumping in the Bay of Bengal. Soldiers of the 769th Chemical Depot Company again played an important role in preparations for that dump. Thirty African American enlisted men and one white officer (Capt. Woodrow Shaver) from the 769th traveled from Kalaikunda to Ondal. At Ondal, they helped the all-white 771st Chemical Depot Company transfer liquid mustard agent from 5000 leaking M47A2 bombs into 1200 drums. The drums of mustard became part of the May ocean dump and the empty bomb casings were buried at Ondal.

On August 4, 1945, the 769th Chemical Depot Company left Kalaikunda for the Mariana Islands, expecting to rejoin the B-29 bomber group they supported. They were at sea on the USS General E. T. Collins when Japan surrendered.

Most of the toxic chemical bombs in India had been dumped in May. Many remained after the war ended, however, including cyanogen-chloride bombs retrieved from the distant base at Shamshernagar. As viewed by the 771st Chemical Depot Company at Ondal, it was still the 100-pound M47A2 mustard-filled bombs that posed the biggest problem. Fifteen thousand of these were judged too prone to leaks for shipment by rail. With assistance from other trained toxic gas handlers like those from the 769th, these leak-prone bombs could have been emptied into drums for safer shipment. Without such assistance, the bombs were instead buried onsite, still filled with mustard agent. Burial was completed on October 12, 1945. The final rail shipment of toxic chemical bombs left Ondal on November 11, 1945, and was dumped at sea soon afterward.