Malaysia Airlines Flight 17 was traveling from Amsterdam to Kuala Lumpur in July 2014. The airline was shot out of the sky with 298 people on board over eastern Ukraine. The Dutch Safety Board released its report on Oct. 13; a number of questions remain. (Jason Aldag/The Washington Post)

MOSCOW — A Russian-developed Buk missile detonated less than a yard away from Malaysia Airlines Flight 17's cockpit, causing the plane to break up over eastern Ukraine so quickly that it is likely the nearly 300 people aboard "were barely able to comprehend the situation" before they perished, Dutch investigators said Tuesday.

The long-awaited findings by the Dutch Safety Board offered a chilling account of the devastation aboard the Kuala Lumpur-bound airliner that was blown out of the sky over eastern Ukraine on July 17, 2014. The report marks the latest stage of evidence gathering as investigators try to sort out what happened to the plane, whose flight path took it directly over the war-torn region.

[How investigators tackled the mystery of Flight 17]

But the findings left unresolved the central question of responsibility, which became even murkier this week with conflicting reports from the missile's manufacturer. The report also did not specify what generation of missile brought down the plane. The Buk surface-to-air missile system, first developed in early 1970s by the Soviet Union, is part of the Russian arsenal and is a complicated air defense weapon designed to locate and engage targets by radar. While older versions are no longer in use by the Russians, various types of Buk systems are used by Ukraine and some other former Soviet republics.

"A 9n314m warhead detonated outside the airplane to the left side of the cockpit. This fits the kind of warhead installed in the Buk surface-to-air missile system,” said Safety Board head Tjibbe Joustra. An animated reconstruction of the impact released by the board detailed how the missile can travel at three times the speed of sound and detonate via proximity fuse; about 800 "pre-formed fragments" struck the jet.

"This impact, combined with the blast of the explosion, causes the cockpit and the business class section to separate," the video notes. "As it descends, the airplane disintegrates."

The report added that "it cannot be ruled out that some occupants remained conscious” during the 60 to 90 seconds before the debris spilled across the Ukrainian countryside, including a field of sunflowers in full bloom. But there was no evidence of "any conscious actions” such as text messages or calls from mobile phones.

[Obama says Malaysian plane shot down by missile from rebel-held part of Ukraine]

In its announcement, the board also noted that Ukraine should have closed off its airspace to civilian planes. It said the Boeing 777, carrying 298 people, should not have been flying over a war zone between Ukrainian forces and separatists backed by Moscow after departing from Amsterdam. But about 160 planes crossed the area of eastern Ukraine the day the flight was shot down.

The Dutch-led probe is not over. A separate criminal investigation is underway, and Dutch Prime Minister Mark Rutte asked Russia for "complete cooperation."

An international team of prosecutors looking into the downing said it had identified “persons of interest” but gave no further details, the Reuters news agency reported. A White House statement called the Dutch report an "important milestone in the effort to hold accountable those responsible."

Western officials and experts blamed separatist forces, who they said were being aided by the Russian military. Russia responded by pointing the finger at the West, saying that Ukraine's army may have shot down the plane and that Ukraine's government was complicit in the passengers' deaths for allowing a jetliner to fly through a war zone.

National Security Council spokesman Ned Price said Washington's assessment remains unaltered. “MH-17 was shot down by a surface-to-air missile fired from separatist-controlled territory in eastern Ukraine,” he said.

But disputes immediately flared, suggesting Moscow could dig in.

Russia's deputy foreign minister, Sergei Ryabkov, was quoted by Russian media as dismissing the report as "biased" and the result of unspecified "political orders" to reach a conclusion. Dutch experts identified an area from where the missile was fired — a span of about 123 square miles that was believed mostly held by Moscow-backed rebels at the time.

The Dutch Safety Board report discredits at least one Russian theory: that the passenger plane was shot down by a Ukrainian air force jet. But both the Russian and Ukrainian armies have Buk missile systems, and Russian officials can and probably will continue to argue that the Ukrainian army was behind the attack on the plane.

In an effort to buttress that argument, the Russian weapons manufacturer Almaz-Antey destroyed a decommissioned airliner using a Buk missile in a controlled experiment. The goal of the experiment was to show that only the antiquated version of the Buk missile used by Ukraine, and not the modern version used by the Russian military, could have caused the damage done to MH17.

Nick de Larrinaga, Europe editor for IHS Jane’s Defense Weekly, questioned the assertion by the company that Russia no longer operates the missile variant that carries the warhead cited in the report.

“This is not borne out by the evidence, which shows they remained in Russian service and in Russian military stockpiles at the time of the shoot down,” he said in a statement.

"The results of our experiment contradict the Dutch report," said Yan Novikov, general director of the company, at Almaz-Antey's Tuesday conference. "It can now be clearly said that if a rocket was used it was a Buk 9M38, not a Buk 9M38M1, fired from the area of Zaroshchenske."

Tuesday's report is the first official finding by Dutch investigators since they announced that MH17 had been penetrated by "a large number of high-energy objects,” indicating shrapnel from a missile, in September 2014. A Dutch broadcaster, NOS, citing a Ukrainian official earlier attached to the investigation, said that pieces of shrapnel from a Buk missile had been found in the bodies of the passengers (English translation here).

According to Alexander Pustovit, a resident of Donetsk who traveled to the scene the day after the crash, bodies were strewn everywhere, and it took 10 minutes to drive through the debris field.

"It was like a crime scene but nobody cared," Pustovit said. "There were bodies everywhere but no one was around."

The Dutch Safety Board's goal was to answer what, and not who, caused the crash. It was also charged with answering why civilian planes were flying over the conflict area, where separatist forces had brought down more than a dozen Ukrainian aircraft and helicopters in the weeks before the MH17 crash.

A Dutch police investigation has released an appeal for witnesses who saw a Buk missile system being hauled on a trailer in separatist-held Ukraine shortly before and after the attack on MH17. The video said that a missile fired from separatist-held territory was the "main version of the investigation," although others are being considered.

Almost from the outset, Dutch investigators suspected that either a missile or an internal explosion caused MH17 to shatter and fall to the earth in pieces. Airliners simply don't fall apart once they have reached a comfortable cruising altitude.

Once the human remains were removed, investigators zeroed in on the thin aluminum skin of the aircraft, looking for tell-tale signs that it had been peppered with shrapnel from a missile designed to explode in close proximity to an airplane.

Suspicions that a missile was the culprit were boosted after rebels delayed and hindered investigators' access to the debris field.

The video's version of events relied heavily on two sources: open-source imagery of a Buk system in separatist-held Ukraine, much of which has been compiled here by the amateur investigative Web site Bellingcat, and audio from tapped telephone conversations between separatist fighters released by the Ukrainian government. The Russian government television station RT (formerly Russia Today) released reports last week attacking Bellingcat and the open-source evidence that separatist forces had a Buk missile system.

Dutch investigators face one other hurdle: finding a venue to bring the accused to justice. In July, Russia vetoed a United Nations Security Council resolution that would have established an international criminal tribunal to investigate the MH17 attack. Russian U.N. Ambassador Vitaly Churkin said his country vetoed the resolution because it was politically motivated. Australia, Belgium, Malaysia, the Netherlands and Ukraine may set up an independent tribunal instead, Australian Foreign Minister Julie Bishop said last month.

Murphy and Gibbons-Neff reported from Washington. Ashley Halsey III in Washington contributed to this report. 

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