Malaysia Airlines Flight 17 (cross-listed as KLM Flight 4103), a Boeing 777 carrying 298 passengers and crew, has been shot down over eastern Ukraine. There are no survivors. The plane was en-route from Amsterdam, Netherlands, to Kuala Lumpur, Malaysia, and was struck by a Russian-built Buk surface-to-air missile while flying at its 33,000 foot cruise altitude. It crashed thirty miles from the Russian border near the village of Hrabove. The crash site is in a contested region claimed by both Ukraine and the Donetsk People’s Republic, an independent state proclaimed by separatists in the region allied with Russia.

Leaders of the Ukrainian government, the Russian government, and the Donetsk separatists have all denied responsibility for the attack, but it now appears that the separatists—with or without Russian support—downed the plane. Separatists have shot down several Ukrainian cargo planes and fighters in recent weeks, and are also known to have obtained a Buk missile launcher following the capture of a military base in the region. Both Russia and Ukraine also operate Buk missile launchers. Around the same time that Flight 17 went down, separatists claimed to have shot down a cargo plane nearby, but that claim was quickly retracted when it became clear that a civilian airliner had been hit.

It has been reported that Donetsk officials have so-far refused to allow Ukraine or international investigators access to the crash site. There are also unconfirmed reports that the plane’s voice and data recorders will be transported to Moscow, Russia.

The U.S. Federal Aviation Administration (FAA) has prohibited U.S. airlines from flying through certain areas of Ukraine’s airspace since April due to concerns about violence and instability (FDC NOTAM 4/7667). The same FAA notice recommended that pilots exercise ‘extreme caution’ if they choose to fly elsewhere in Ukraine. Ukraine and Russia have been embroiled in a military crisis since Russian troops invaded and occupied the Crimean peninsula earlier this year. Russia has since annexed Crimea, but most of the international community does not recognize the legitimacy of the annexation. Fighting continues in other areas between separatists who desire to join with Russia and the Ukrainian military.

In March of this year, another Boeing 777 operated by Malaysia Airlines—Flight 370—disappeared shortly after departing from Kuala Lumpur en-route to Beijing, China. There were 239 passengers and crew aboard. That plane is presumed crashed in the Indian Ocean with all lives lost. Despite the most expansive search in history, no crash site or debris has yet been found.

There have been a number of airline shoot-down incidents in the past. In three notable incidents, Korean Air Lines Flight 007 was shot down by Soviet (Russian) forces in 1983, Iran Air Flight 655 was shot down by the U.S. Navy in 1988, and Siberia Airlines Flight 1812 was shot down during a Ukrainian missile exercise in 2001.