The Il-76 is a workhorse - Soviet-designed in the 1970s for arctic supply runs and military airlift, with a hinged rear ramp sized for tanks. What it was not designed for was passenger service. Ukrainian Cargo Airways, a state-owned Kyiv operator, flew UR-UCB on freight charters across Africa and the former Soviet space. The 8 May run was a two-hour hop across the Democratic Republic of the Congo, a country so vast and so roadless that the air force moves troops by whatever aircraft it can lease. Survivors later described the cargo hold as packed: people crammed onto benches and on the floor, sleeping wherever they could find room, with a secured truck taking up the middle of the bay. The truck, it would turn out, may have saved lives.

About 45 minutes after takeoff from Kinshasa, somewhere over the diamond-mining city of Mbuji-Mayi, the rear cargo door swung open. The explosive decompression was instant. People sleeping near the door were blown out into the night before they could wake. Those who were awake grabbed ropes, bags, cargo netting - anything. The plane yawed sharply left and right as the pilots fought for control, and each lurch threw more people toward the opening. 'I was just next to the door,' one survivor told reporters, 'and I had the chance to grab onto a ladder just before the door let loose.' Another remembered seeing a soldier holding a baby, and a mother holding another baby, both ripped out of the aircraft together. The truck in the middle of the hold acted as a partial barrier. Everything aft of it was lost.

The pilots somehow held the aircraft together and returned to Kinshasa. How many people were still on board when they landed depended on who was counting. The Congolese government confirmed 17 dead. Other government officials said 60. Airport officials said 129. Aviation authorities and Western diplomats estimated at least 170. Some survivors, pressed for numbers, said as many as 200 had been killed. Only about 40 percent of the people who had boarded at Kinshasa walked off the plane at Kinshasa. At least two pregnant women among the survivors miscarried from shock. A Ukrainian defence ministry spokesman told the press that no one had been hurt. The discrepancy - between 17 dead and 200 dead - was never officially resolved. The missing were soldiers, wives, children, babies. The search parties the Congolese government dispatched across the countryside below the flight path never recovered most of them.

A military investigation began immediately. The findings, as they trickled out, pointed not to exotic mechanical failure but to something more mundane and more damning. Sergeant Kabamba Kashala testified that the cargo door had not been properly fastened before takeoff - and that the crew had made three attempts to fully close it in flight, unsuccessfully, before it blew open. The pilot offered two theories: either a passenger had tampered with the door controls, or a computer glitch had released the latches. The door's control panel, on an aircraft built for a trained military crew, was accessible to people sleeping in the hold beside it. Whether a frightened or curious passenger had touched a button, or whether the door had simply been inadequately latched from the start, remains the central unanswered question. What is clear is that a plane designed for cargo was being used to transport human beings in conditions that offered them no protection at all.

Most writeups of this accident focus on the aircraft - the registration, the operator, the door design - and treat the death toll as a technical footnote. The uncertainty itself tells the real story. In the vast interior of the Democratic Republic of the Congo in 2003, in the middle of a civil war that had killed millions, the lives lost from an airplane in the sky were not individually recorded. The 'passenger manifest' did not exist in any meaningful sense. The families on board were not counted onto the aircraft, and so they could not be counted off it. Somewhere below the Il-76's flight path, across the forests and plateaus east of Kinshasa, lay dozens or perhaps hundreds of Congolese soldiers, their wives, and their children. They had names. They had families waiting for them in Lubumbashi. Most of those names never entered any record that reached the outside world.