Who Killed Hammarskjold

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), 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 fifteen 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 Hammarskjöld 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?