[sonsofliberty2000]

Another:

Reports of "air conditioning problems" are rather odd given the crew obviously became incapacitated. Had there been a real problem the crew would immediately don oxygen masks as a precaution whilst reporting the problem.

Lack of oxygen, whilst it quickly befuddles, doesn't immediately incapacitate and there are very definite procedures to be followed. There have been cases of Lear Jets (one US, one German) where the air conditioning/oxygen failed and the crew passed out BUT these were at cruise levels above 36,000 and there was no notification from the crew.

Given that this aircraft seems to have impacted a mountain, unless the voice recorders give some more info, the post mortems will be critical to answering what looks to be a rather odd set of circumstances.

[Prophet in the wilderness]

We hopefully will know more when they examine the black boxes.
Don't the pilots have a portable oxygen bottle next to them or under their seat ?
Some reports are saying that the pilot left the flight deck and was in the PAX ( passenger cabin ) cabin, because one of the passengers managed to send a text message on the phone to their relative and said the pilots face was blue.