Investigators are looking into whether Russian anti-aircraft defenses may have played a role in the deadly plane crash in Kazakhstan. Many questions remain about why the plane was diverted and what led to the crash that killed dozens.

After an Azerbaijan Airlines jet crashed in Kazakhstan, speculation mounted about why the plane went down and whether possible Russian air defense action may have played a role.

Thirty-eight of 67 onboard flight from Baku to the Chechen city Grozny believed to have been killed. Russian authorities cite bird strike.