The crash site of the Malaysia Airlines flight in eastern Ukraine holds many important clues about what happened to the plane. But that site is under the control of pro-Russian separatists who are suspected of involvement in shooting the plane down.
The rebel fighters say they are giving access to investigators, including those from the Ukrainian government, though one Ukrainian official who visited the scene Friday said he was not given full access.
Here are some of the key questions on the investigation into Flight MH17:
The U.N. Security Council called for a "thorough and independent investigation" of the downing of this plane. Is that possible, in the middle of a war zone?
It's likely to be very difficult. Even though there's been talk of a cease-fire to facilitate an investigation, there were reports of fighting Friday within earshot of the wreckage site.
Normally, a crash like this would be investigated by the country in whose airspace it took place.
Pro-Russian paramilitary groups have declared independence in the region, and they've been claiming the airspace, too.
The separatists said today that they would allow investigators access to the site, including international experts.
A team of international monitors did visit the site today. Any word from them?
About 30 observers and experts from the Organization for Security and Cooperation in Europe visited the scene.
The regional governor, who is on the side of the Ukrainian government, charged that the paramilitaries were interfering with the investigation and not giving the experts full access to the wreckage.
What would the investigators be looking for?
Some outside analysts have said the experts may be able to figure out where the plane was hit and determine the missile's trajectory.
That could show where the missile was fired from.
They'll also be looking for fragments of the missile itself, because these weapons generally have markings that show where and when they were made.
One big problem is that the plane was apparently hit at high altitude and the debris and bodies of passengers came down over a very wide area.
Videos show that the site is not very secure — there have been armed men and volunteers tramping around and going through the wreckage, so no matter what the outcome of the investigation might be, there will probably be allegations of evidence-tampering.
There's been a lot of attention to the missile that supposedly brought this plane down. What do we know?
Ukrainian officials say the missile was a Soviet and Russian type known as the SA-11 Buk missile system.
A lot of the discussion has focused on where the paramilitaries would have gotten these weapons and how they would have been able to operate them well enough to hit a fast-moving target at 33,000 feet.
The Ukrainian ambassador to the U.N. said that Ukrainian intelligence has videos and photos showing the rebels have at least two of these systems.
The systems are very complex to operate. It takes a lot of training to use one effectively, so Ukrainian officials are also suggesting that Russian soldiers may have been assisting or manning the weapon.
There was a lot of contradictory talk about the black boxes, the flight data and voice recorders from the plane. Do we know now who has them?
It's unclear now who has them. But the one piece of news that came out was that Russia says it doesn't intend to take custody of the boxes and that they should be handed over to international investigators.
That could be a way to pre-empt claims from Ukraine that Russia somehow manipulated the data to protect the paramilitaries.
AUDIE CORNISH, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.
ROBERT SIEGEL, HOST:
And I'm Robert Siegel. President Obama says, the Malaysian plane that crashed in eastern Ukraine was shot down by a surface-to-air missile fired from territory controlled by pro-Russian separatists. Two-hundred-ninety-eight people were on that jet. Mr. Obama stopped short of pointing the finger directly at Russian president Vladimir Putin, but he clearly put the blame on the separatists.
(SOUNDBITE OF NEW CONFERENCE)
PRESIDENT BARACK OBAMA: We know that they are heavily armed and that they are trained, and we know that that's not an accident. That is happening because of Russian support.
SIEGEL: The president's comments in a news conference today echoed those made earlier by the U.S. ambassador to the United Nations. This morning, during an emergency meeting of the U.N. Security Council, Samantha Power called on Russia to assist in allowing a full investigation into the crash and to calm tensions.
SAMANTHA POWER: This tragedy only underscores the urgency and determination with which we insist that Russia immediately take concrete steps to de-escalate the situation in Ukraine.
SIEGEL: Rebel fighters control the sight of the wreckage in Ukraine, and they say that they're giving access to investigators. NPR's Corey Flintoff joins us now with more. And Corey, the U.N. Security Council called for a thorough and independent investigation of the downing of this plant. How possible is that in the middle of a war zone?
COREY FLINTOFF, BYLINE: It's likely to be very difficult, Robert. You know, even though there's been talk of a cease-fire to facilitate an investigation, there were reports of fighting today within an earshot of the wreckage site. Normally, you know, a crash like this would be investigated by the country in whose air space it took place, but these paramilitary groups have declared independence in the region, and they've been claiming the airspace. The separatists did say today, they'd allow investigators access to the site, as you mentioned just now, including experts from the Ukrainian government.
SIEGEL: We are hearing that a team of international monitors visited the site today. Any word from them?
FLINTOFF: Well, a group of observers and experts from the Organization for Security and Cooperation in Europe did visit the scene today. But they later told the Reuters News Agency that they didn't get the access that they needed. They didn't give freedom of movement, and they didn't get enough time to work. So a spokesman for the group said, they'll try again tomorrow.
SIEGEL: Once the official investigation is underway, what do you assume the focus will be?
FLINTOFF: Well, some outside analysts have said, they may be able to figure out where the plane was hit and then determine from that roughly where the missile was fired from. Of course, they'll also be looking for fragments of the missile itself because these weapons generally have markings that show where and when they were made. One big problem here is that this plane, of course, was hit at a very high altitude, and the debris and the bodies of passengers came down over a very wide area.
We saw in videos yesterday that the site is not secure. There were armed men and volunteers tramping around and going through the wreckage. So no matter what the outcome of the investigation might be, there's probably going to be allegations of evidence tampering.
SIEGEL: There has been a lot of discussion of the missile that's said to have brought the plane down. Did you learn anything more about it today. Well, Ukrainian officials say, the missile was a Soviet and Russian type. It's known as the SA-11. They call it a Buk missile system. There was a lot of discussion today focused on where the paramilitaries would've gotten these weapons and how they would've been able to operate them well enough to hit what was a very fast-moving target at 33,000 feet.
The Ukrainian ambassador to the U.N. said today that Ukraine intelligence has videos showing the rebels have at least two of these things. They're very complex to operate, and it apparently takes a lot of training to use one of effectively. So Ukrainian officials are suggesting that Russian soldiers may have been involved in manning this weapon.
SIEGEL: And in a word, we know where the black boxes are from this plane?
FLINTOFF: It's pretty unclear. One piece of news today was that Russia said, it didn't intend to take custody of the boxes, and they should be handed over to international investigators.
SIEGEL: That's NPR's Corey Flintoff. Corey, thank you.
FLINTOFF: Thank you, Robert. Transcript provided by NPR, Copyright NPR.