On Tuesday, December 27, members of Russia's Emergency Ministry pack a flight recorder recovered from a Russian military plane that crashed Sunday into the Black Sea with 92 people aboard. Russia's transport minister said it was assumed the plane had crashed due to technical malfunction or pilot error -- not terrorism. Rossiya One TV Channel/AP

Emergency Ministry personnel prepare a submersible craft Tuesday to search for sunken wreckage and victims' remains. Thirteen bodies had been recovered from the Black Sea as of Tuesday morning. Rossiya One TV Channel/AP

A woman lights a candle Tuesday next to makeshift memorial in Sochi, Russia, for Russian activist Elizaveta Glinka, who was killed in the crash. Also presumed dead were nine journalists and more than 60 members of the Russian army's official choir, the Alexandrov Ensemble. VASILY MAXIMOV/AFP/Getty Images

Wreckage from the Tu-154 plane is hauled from the Black Sea late on Monday, December 26. Vladimir Velengurin/Emergency Situations Ministry Handout/AP

Emergency crews continue search operations on December 26. Viktor Klyushin/AP

People visit a makeshift memorial to victims of the crash at a pier in Sochi on December 26. Russia is observing a national day of mourning for the eight crew and 84 passengers aboard. VASILY MAXIMOV/AFP/AFP/Getty Images

A Russian police orchestra musician places a flower in tribute to members of the Alexandrov Ensemble outside their home stage building in Moscow on December 26. The popular ensemble was scheduled to perform for Russian pilots in Syria ahead of New Year's Day. NATALIA KOLESNIKOVA/AFP/Getty Images

People hold a candlelight vigil for victims of the crash on Sunday, December 25, in Sochi. Viktor Klyushin/AP

Russian emergency personnel work near the site of the crash on December 25. The plane was en route from Moscow to Syria and had stopped in Sochi to refuel. Viktor Klyushin/AP

Russian emergency workers carry remains from the wreckage of the Tu-154 plane that crashed near Sochi on December 25. Viktor Klyushin/AP

Russian President Vladimir Putin, left, and Nursultan Nazarbayev, president of Kazakhstan, speak to members of the media in St. Petersburg, Russia, on December 25. Putin has ordered Prime Minister Dmitry Medvedev to lead an investigation of the crash, Russian news agency Sputnik reported. Mikhail Klimentyev/TASS/Getty Images

Russian police secure the area near where the plane crashed. In addition to the ensemble, the plane was carrying eight crew, eight soldiers and nine journalists. Viktor Klyushin/AP

A man places a candle outside the building of the famed Alexandrov Ensemble, the Russian army's official dance and choir company, in Moscow. Pavel Golovkin/AP

A man places flowers outside the building of the Alexandrov Ensemble in Moscow on Sunday. Alexander Kibovsky, head of Moscow's culture department, called them "our cultural paratroopers." ALEXANDER UTKIN/AFP/Getty Images

Flowers lay in front of a photo of the Alexandrov Ensemble at the group's building in Moscow. "These people always performed in war zones, they wore uniforms, they brought kindness and light," Kibovsky said. Pavel Golovkin/AP

Two women stand outside Alexandrov Hall, a rehearsal room of the Alexandrov Ensemble, in Moscow on Sunday. The ensemble, established in 1928, has toured the world performing Russian folk songs, World War II anthems and patriotic music. Mikhail Japaridze/TASS/Getty Images

Photographs of Channel One, NTV and Zvezda TV journalists killed in the plane crash are seen outside the Ostankino Technical Center in Moscow. Artyom Geodakyan/TASS/Getty Images