Malaysian plane shot down in Ukraine: What happened?

Updated 12:02 PM EDT, Sat July 19, 2014

Story highlights

NEW: Donetsk rebel official: Plane shot down, but not by us

Malaysian official says the crash site's integrity has been compromised

President Obama says evidence points to a missile strike by pro-Russian rebels

Russia could face increasing international isolation and tougher sanctions

(CNN) —  

It’s an international air disaster in a war zone – a commercial flight with almost 300 people on board shot down in eastern Ukraine.

As new details emerge, here is a look at basic questions about the tragedy:

Was the plane shot down?

All evidence so far says yes.

President Barack Obama declared Friday that a surface-to-air missile blasted the Malaysia Airlines Boeing 777 on Thursday over the Donetsk region of Ukraine near the Russian border.

According to a senior American official, a U.S. radar system saw a surface-to-air missile system turn on and track an aircraft right before plane went down.

A second system saw a heat signature, which would indicate a missile rising from the ground into the air at the time the airliner was hit, the official explained.

Does anyone dispute that?

Not at this point.

While the Ukrainian government trades accusations of blame with pro-Russian rebels it is fighting in eastern Ukraine and Russia itself, no one has offered evidence of an alternative theory.

The plane’s debris field indicates a mid-air explosion.

Who did it?

A preliminary classified U.S. intelligence analysis concludes the rebels most likely fired the missile, according to an American defense official with direct access to the latest information.

“Evidence indicates that the plane was shot down by a surface-to-air missile that was launched from an area that is controlled by Russian-backed separatists inside of Ukraine,” Obama told reporters. However, he stopped short of blaming any particular group.

Ukrainian officials accused the rebels, who denied it. Russia also denied involvement.

Now Ukrainian officials have released what they say are intercepted communications in which rebels talk about downing the civilian airliner.

CNN had no way of immediately verifying the authenticity of the audio recordings.

The leader of the rebels in Donetsk said Saturday he believed the flight was shot down, but Alexander Borodai reiterated his denial that his forces did it.

What kind of missile was used?