“spontaneously lost both engines”
How does that happen? Pilot or copilot error? Intentional? Bad fuel? Electronics failure?
While undoubtedly rare, a double bird strike is a possiblity.
I’m not saying that was it. The investigation will tell.
My guesses: the plane ran out of fuel; the pilots failed or were unable to transfer or access fuel internally; or the fuel was contaminated with condensate water. My guess is that the immediate cause will be determined fairly quickly and completely, with lots of arguing to follow as to whether and how human factors contributed.
Improperly swapped fuel tanks? Forgot to start second fuel pump? Lined up the empty(er) tank and not the full one?
The passengers got out because they had access to a cabin door. The pilots were isolated by their location. They would have to climb out of their seats and possibly circumvent a bulkhead to get out. It is likely also, from the wreckage pictures, that the cockpit section sustained significant impact damage.