Russian airplane crashed in Egypt’s Sinai on 31 October, which killed all 224 people on board.
The casualties were 217 passengers including 25 children and 7 crew members.
Russian investigator, Viktor Sorochenko said the Airbus A321 travelling from Sharm El-Sheikh to St Petersburg had broken apart in midair.
Broken fragments are strewn over 20 square kilometre, according to his statement.
The pilot sensed technical failure and reported it to the air traffic controllers before the crash. However, since then the pilot did not make any emergency calls with the air traffic control, according to both Russian and Egyptian investigators.
The Russian airline Kogalymavia deputy general director Alexander Smirnov said the only possible explanation of the crash could be “an external impact on the airplane.”
The Islamic State of Iraq and Syria (ISIS) claimed the responsibility for the crash in social media. However, Egyptian authorities denied this as it is unlikely that ISIS had the capacity to attack the airplane flying at an altitude of 9450 meters (31,004 ft).
In addition, there is no “direct evidence” that ISIS was to blame for the crash, according to the US Director of National Intelligence.
Investigation has not yet decoded the black boxes.