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.

Azerbaijan Airlines’ Embraer 190 was en route from the Azerbaijani capital of Baku to Grozny in the North Caucasus on Wednesday when it was diverted. It crashed while trying to land near the city of Aktau, Kazakhstan, after flying hundreds of kilometers (miles) east across the Caspian Sea.

Flight records for the plane made by Brazil's Embraer that crashed last week in Kazakhstan are headed to the South American country so the data can be extracted, the Brazilian Air Force said in a statement on Monday.