Maria Ivleva  15, was one of the first victims to die in the tragedy, caused by an explosion under her seat, 31B, that went off with the power of 'a kilo of TNT',Daily Mail reports.Forensic tests have now narrowed down the epicentre of the explosion above the Sinai to rows 30 or 31 on the Airbus A321.
Investigators say that the bomb would have killed those nearby almost instantly, with the blast-zone ranging from rows 27 to 32. Others may have been caught in the chaos caused by the massive hole in the tail of the plane left by the blast, as it descended rapidly from 31,000 ft.
 Isis has since claimed responsibility for the explosion, which they say was caused by an improvised explosive device made from a drinks can.