yes, its a guess, say again GUESS:
non precision approach, night or semi night conditions , wondering if they had the runway in sight and lost it in low scud, or somehow decieved by low hanging cloud or a sudden spurt of rain/drizzle without wipers on, a bit of a duck under mda and contact with terrain.
Let's try this one again, ( ok MOD?)
It is just a guess and out of line. The bodies aren't even room temperature and we have to put up with the start of endless guesses from the PPrune crowd, many who aren't aircrew and should confine themselves to the spectators or enthusiast forum for their comments and questions.