From flydive's first link.
The plane which can seat 20 passengers was empty when the captain, the second pilot and a flight attendant boarded the aircraft for pre-flight checks. At that moment, the door detached from the fuselage and hit the pilot. It came off with such force that the 50-year-old man died on the spot, while parts of the door were then found some ten meters away from the aircraft, investigators say.
Baggage door it would seem to me. Left open in strong wind? Where is the METAR when you need it.