People walk amongst the debris at the crash site of Malaysia Flight 17 in eastern Ukraine.

 

 

 

 

What we know:

• Malaysia Airlines Flight 17 was brought down by a surface-to-air missile, U.S. concludes 
• Ukrainian President Petro Poroshenko calls the loss of the plane over Donetsk a "terrorist action"
• Investigation has begun, with some experts cautioning that it must involve parties not involved in the ongoing Ukraine-Russia strife
• There were 280 passengers and 15 crew on board, flying from Amsterdam to Kuala Lumpur