On 18 September 1961, the second UN secretary general, Dag Hammarskjold, was killed in a mysterious plane crash in the Zambian town of Ndola. He was on a mission to resolve the crisis that convulsed Congo in the first months of its independence. Britain, Belgium, the USA, South Africa and the white Rhodesians were immediately suspected of murdering him. The Swede, who became secretary general in 1953, had said only the year before that "the hardest thing of all-to die rightly - [is] an exam nobody is spared, and how many pass it?" Did Dag die rightly? In a sensational new investigative book (left), out in London on 13 October, Susan Williams probes the controversy. Below is an extract from the book.
BETWEEN 10 AND 15 MINUTES AFTER MIDNIGHT ON Monday 18 September 1961, a DC-6B aircraft crashed near the airport of Ndola, a town in the British colony of Northern Rhodesia (now Zambia), not far from the Congo border. The plane had flown from Leopoldville (now Kinshasa) and was taking Dag Hammarskjold, the UN secretary general, and his entourage, on a mission to try to bring peace to Congo.
It was reported that only one of the 16 passengers was found alive - Harold Julien, chief of security, who died six days later. Questions were asked as strange details of the crash emerged. Given that Ndola air traffic control had seen the plane flying overhead and had granted the pilot permission to land, why did the airport manager close down the airport?
Why did Lord Alport, the British high commissioner in Salisbury (now Harare, the Zimbabwean capital), who was at the airport, insist that the secretary general must have decided "to go elsewhere"?
Why did it take until four hours after daybreak to start a search, even though local residents, policemen and soldiers reported seeing a great flash of light in the sky shortly after midnight?
Why was the missing aircraft not found for a full 15 hours, even though it was just eight miles away from the airport where it had been expected to land?
What about the second plane that had been seen to follow the secretary general's aircraft? Why did the survivor refer to an explosion before the crash?
Why did Hammarskjold have no burns, when the other victims were so badly charred? How did he escape the intense blaze, which destroyed 75 to 80 per cent of the fuselage?
Two days after the crash, the Rhodesian Federal Department of Civil Aviation set up an air accident investigation, as required by the international civil aviation authorities. The report concluded that the approach to the airport was normal and correct, except that it was about 1,700 feet lower than it should have been.
It stated that the evidence available did not allow for a "specific or definite cause" for the crash, because so much of the aircraft had been destroyed and there was so little information from the single survivor.
While it observed that pilot error was a possibility, it was unable to rule out the "wilful act of some person or persons unknown which might have forced the aircraft to descend or collide with the trees".
This initial investigation was followed by two major public inquiries. The first was conducted by a Rhodesian commission, which produced its report in February 1962. It concluded that the crash was an accident, caused by pilot error.
The second major public inquiry was conducted by a UN commission. Unlike the Rhodesian inquiry, it delivered an open verdict on the cause of the crash when it produced its report in April 1962.
It argued that, as no special guard was provided for the plane prior to its departure from Leopoldville airport, an un authorised approach to the aircraft for purposes of sabotage "cannot be excluded": although the doors were said to have been locked when the plane was parked at Leopoldville, access was possible to the hydraulic compartment, the heating system, and the undercarriage.
The commission added that it "cannot exclude attack as a possible cause of the crash". Concern was expressed at the delay in the search and rescue procedures, particularly since the plane crashed not far from an airfield on which 18 Rhodesian military aircraft, capable of carrying out an air search, were stationed.
Controversy over the cause of the crash continued. Thirty years later, international interest was revived by a letter written to the British newspaper, The Guardian, on 9 November 1992 by two former UN officials, George Ivan Smith and Conor Cruise O'Brien. The heading of the letter made its contents clear - Hammarskjold plane crash no accident'.
In order to investigate Smith and O'Brien's findings, the Swedish Ministry for Foreign Affairs authorised a further inquiry into the crash. The inquiry, which was a small-scale investigation, was conducted by Bengt Rosio, formerly the Swedish consul and head of mission in the Congo in the early 1960s and then a career diplomat in the Swedish Foreign Service.
Rosio produced a report in 1993, in which he concluded that the "least improbable" cause for the crash was CFIT - "Controlled Flight Into Terrain". According to this theory, the pilot made an error in judgement regarding altitude, due to a sensory or optical illusion, which made him fly too low and crash into the trees.
Rosio's perception of the crash was not new, judging by a British official document from October 1961. This records that after a nine-day visit to Ndola, Rosio visited the first secretary at the British embassy in Leopoldville and said he was "personally satisfied that the crash was an accident and had been due to pilot's error".
He then listed the reasons why Swedish experts were critical of the Rhodesian investigation. Rosio's purpose, reported the first secretary to the Foreign Office in London, "was I believe to help us and the Rhodesian authorities ... and to give us the opportunity to avert subsequent criticism, particularly by the Afro-Asians".
Not one of these investigations has laid to rest the continuing suspicions about the crash of the plane that ended the lives of Secretary General Hammarskjold and the other passengers and crew.
Conspiracy theories have proliferated--in the press, in books, and especially on the Internet. But, in addition, serious legitimate concerns have failed to go away, even after nearly 50 years.
In 2005, Major General Bjorn Egge, a Norwegian who had been the UN's head of military information in the Congo in 1961, with the rank of a colonel, suggested that Hammarskjold had a round hole in his forehead that was possibly consistent with a bullet hole.
Now 87 years of age, Egge explained in a statement to the Norwegian newspaper, Aftenposten, that straight after the crash in 1961, he had been sent to Ndola to collect the secretary general's cipher machine and his briefcase, and had been allowed to see his dead body in the mortuary. The body seemed to have a hole in the forehead.
Egge said: "He was not burnt as were the other ... casualties, but had a round hole in his forehead. On photos taken of the body, however, this hole has been removed. I have always asked myself why this was done. Similarly, the autopsy report has been removed from the case papers. Again, I ask why?" He added: "When I saw Hammarskjold's body at the hospital, two British doctors were present but not very willing to cooperate. However, I noticed the hole in Hammarskjold's forehead in particular."
Egge qualified his statement carefully in an interview with Aftenposten 10 days later. He said there was no tangible evidence that Hammarskjold's death was the result of a conscious act by a third party, but that circumstantial evidence pointed in this direction.
There have been ongoing suspicions, too, about the bullets found in the bodies of two of the security guards; the presence of these bullets was attributed by the Rhodesian inquiry report to the explosions of cartridge cases in the fire.
But at the time, the bullets led to considerable suspicion, expressed in particular by Major C. F. Westrell, a Swedish explosives expert. "From my experience," said Westrell, "I can firmly state that ammunition for rifles, heavy machine-guns and pistols cannot, when heated by fire, eject bullets with sufficient force for the bullets to get into a human body."
He based this statement on the results of some large-scale experiments to investigate the danger for firemen in approaching burning ammunition stores. His opinion was shared by Arne Svensson, chief of the technical department of the police in Stockholm, who said that if bullets were found in any of the victims of the air crash, they must have passed through the barrel of a weapon.
He also said that if a security guard had had an ammunition pouch placed close to his body and the ammunition was exploded by the heat of the fire, the walls of the pouch would have diminished the power of the explosion. In such circumstances, it is almost impossible for the bullets to go through clothes. These suspicions about the bullets have persisted.
Questions have also been asked about holes in the aircraft: whether or not they had been caused by bullets.
One of these holes was a perforation in the nose dome, with a fracture immediately below it...