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?

Russian President Vladimir Putin apologized for the plane crash in Russian air space on Christmas Day that left 38 people dead in a statement that said Russia was targeting Ukrainian drones over the plane’s planned destination at the time, but stopped short of taking responsibility.

Survivors of the Azerbaijan Airlines plane that crashed in Kazakhstan on Christmas Day say they heard at least one loud bang before the aircraft crashed.

The Kremlin has said that the Russian president "apologized for the tragic incident" and expressed his "deep and sincere condolences" to the victims' families.

Russian President Vladimir Putin apologized to the President of Azerbaijan for the crash of the civilian airliner that killed 38 people, the Kremlin said Saturday, stopping short of admitting responsibility.

Russian President Vladimir Putin has apologized to his Azerbaijani counterpart for what he called a “tragic incident” following the crash of an Azerbaijani airliner in Kazakhstan that killed 38 people

On Christmas Day, a plane traveling from Baku, Azerbaijan, to Grozny, Russia, crashed in Kazakhstan, killing over half of its passengers. Theories abound regarding why the plane made an emergency landing near the Kazakhstani city of Aktau.

Russian President Vladimir Putin apologized to his Azerbaijani counterpart after an incident in Russian airspace that led to the crash of an Azerbaijan Airlines passenger aircraft on Dec. 25, killing dozens.

An Azerbaijan Airlines statement on Dec. 27 blamed “interference” for the Christmas Day plane crash that killed 38 people.