Azerbaijan marked a somber Thursday after a state-owned passenger plane burst into flames after crashing on the shores of the Caspian Sea, killing at least 38 people aboard.

An Azerbaijani airliner has crashed in Kazakhstan after being diverted, killing 38 of 67 people on board. Some experts alleged that the plane went down after being hit by Russian air defense systems. Some things to know about the crash and the speculation about a possible cause:

Questions were being asked Thursday about the cause of an airliner crash in Kazakhstan the day before, as Azerbaijan held a day of mourning for the dozens of victims of