It is being called the worst air disaster in Greek history. 121 people are feared dead after a Cypriot airliner slammed into a mountainside north of Athens on Sunday morning. Authorities have all but ruled out foul play, saying a sudden loss of cabin pressure in the cockpit was probably to blame. Two Greek military jets were scrambled after air traffic controllers lost contact. One of the airforce pilots said he could not see the captain and that the co-pilot was slumped in his seat.That report was corroborated by a text message sent by one of the doomed passengers to a relative. Analysts say the depressurisation would have happened so quickly that the pilot and his colleague would not have had time to put on oxygen masks and steer the plane to a lower and safter altitude. According to the airline most of the passengers were Greek Cypriots. There was a group of 48 children on their way to Prague, some Greeks, and a few foreigners. Helios Airlines flight number HCY522 was flying from Larnaca to Athens when it came down on the Evvoia peninsula about 40 kilometres from the Greek capital. Helios is a low-cost competitor of the national carrier and has been operating for six years. It has a fleet of Boeing 737s and flies between Cyprus and Athens, London, Sofia, Dublin and Strasbourg. The black box recorders have been recovered and are now being analysed. With the fuselage totally destroyed and only the tail recognisable, officials are saying it would be a miracle if any survivors were found.