A Boeing 737 airliner crashed on landing and burst into flames in the Russian city of Kazan on Sunday, killing all 50 people on board, including a British woman.
The Tatarstan Airlines flight, from Moscow's Domodedovo airport, was making a second attempt to land and exploded when it hit the runway, killing all 44 passengers and six crew on board.
The British woman has been named as Donna Bull, 53, from Cambridge. She worked at Bellerbys College in the town and was visiting Russia on a 10 day work marketing trip.
The list of dead also included Irek Minnikhanov, the son of Tatarstan's governor, and Alexander Antonov, who was head of the Tatarstan branch of the Federal Security Service, the main successor agency to the Soviet-era KGB.
There are currently no indications of what may have caused the crash and it is not clear why the plane's first landing attempt was unsuccessful. Boeing said it would provide assistance to the investigation into the cause.
Sergei Izvolsky, a spokesman for the state aviation agency said: “The plane touched the ground and burst into flames. The cause of the crash as of now is unknown.”
Investigations are said to be centred around whether the crash was caused by a technical or crew failure. Other factors including the weather and quality of fuel will also be considered.
James Pitman, managing director of Study Group which runs Bellerbys Colleges, said: "Donna joined Bellerbys Cambridge in April 2012 as an A-levels programme manager.
"She was a very popular and well respected member of staff and will be sorely missed by both her students and colleagues.
Kazan, the eighth most populous city in Russia, is approximately 450 miles east of Moscow.
Russia has a poor aviation safety record with the country suffering four fatal plane crashes last year and five in 2011.