Plane Crash Questions

As the investigation into the crash of Chalks Ocean Airways flight 101 continues, the bodies of 19 of the 20 passengers who were reportedly aboard the aircraft have been found. In fact, most - if not all - were reportedly still strapped in their seats - including the pilot and co-pilot. And... the plane landed in relatively shallow water after having traveled only a short distance. Rescue workers have been in the water since the plane went down, engaged in a search and recovery operation - looking for the body of the remaining passenger.

So, where is the 20th passenger?

If you haven't done so already, I would urge you to watch the film (from the CNN website) of the plane crashing into the water, and notice the right wing separate from the fuselage. As recounted in the article below, witnesses reported hearing an explosion, then observed the right wing separate from the fuselage. Below is what the inside of a twinin-engine Grumman G-73 Turbo Mallard looks like and it's seating layout.

there are overhead storage bins above the passenger seats in the approximate location where the wing is affixed to the fuselage. Could it be that an onboard explosion, possibly from the contents of a stowed bag, caused the massive structural damage and further caused the wing to separate from the aircraft? Could someone have registered for the flight, placed a bag on board (or in some manner, caused a bag to be taken and stowed on board), but did not board the aircraft? A very thorough investigation will tell the whole story, but before terrorism or criminal activity is summarily dismissed, consider the possibility that the 20th passenger opted not to board the plane - and perhaps remotely detonated an explosive device in the overhead cargo bin as the plane ascended, before it got our of range. As there is no federally mandated screening of parcels for this type of aircraft and in light of the recent threats to airlines, could this have been a test run?