Aviation experts said Thursday an Azerbaijani airliner that crashed in Kazakhstan most likely went down after being hit by Russian air defense systems. Here are some things to know about the crash that killed 38 out of the 67 people on board: How did the plane crash?

In a Dec. 27 phone conversation with Aliyev, Kazakh President Kasym-Jomart Tokayev discussed the progress of work of the special state commission to investigate the crash and assured that the Kazakh side will make every effort to ensure comprehensive and objective clarification of all circumstances of the crash.