About that...
Knew a guy in that flight. Its been 5 years and 3 months or so and the case is still in court (in fact the judge just denied witnesses from Boeing and some other European organization, don't know too much details on it).
And thats how it somehow happened....
"The preliminary investigation reports state that the maintenance performed on the aircraft had left the pressurization control on a 'manual' setting, in which the aircraft would not pressurise automatically on ascending; the pre-takeoff check had not disclosed nor corrected this. As the aircraft passed 10,000 feet (3,000 m), the cabin altitude alert horn sounded. The horn also sounds if the aircraft is not properly set for take off, e.g. flaps not set, and thus it was assumed to be a false warning. The aircrew found a lack of a common language and inadequate English a hindrance in solving the problem. The aircrew called maintenance to ask how to disable the horn, and were told where to find the circuit-breaker. The pilot left his seat to see to the circuit breaker and both aircrew lost consciousness shortly afterwards."
Poor people didn't know what hit them. :(