Malaysian Airlines has lost another Boeing 777 airliner, this time over Ukraine to a missile allegedly fired from a Buk ground-to-air system, according to a Ukrainian source. Reportedly, 295 people (280 passengers, 15 crew) were aboard the plane, on a flight from Amsterdam to Kuala Lumpur.

Undoubtedly there is going to be a lot of finger pointing, with Ukraine claiming Russian-supported rebels shot the missile and Russia blaming Ukraine for the missile.

The actual cause of the crash remains unclear. The BBC lists some possibilities:

A defence expert has told the BBC that shooting down a plane at 10,000m (9.7 miles) would have required a long- range surface-to-air missile - possibly guided by radar.

That suggests it is unlikely it could have been downed by a portable air defence missile, or Manpad, which has a much shorter range.

The only other possibility is for an aircraft at that height to be downed by a fighter carrying air-to-air missiles.

The US will have access to satellite imagery that should be able to identify ultra-violet plumes if a long-range surface-to-air missile was fired.

The BBC also notes that this is far from the first airplane to be shot down over Ukraine recently:

A number of Ukrainian military planes have been shot down by missiles in recent weeks. Ukraine has accused Russia's military of supplying advanced missiles to the rebels.

Earlier on Thursday, Ukrainian officials blamed the Russian air force for shooting down one of its ground attack jets on Wednesday.

God rest the souls of those killed in this travesty.