-- Investigators found red streaks -- transfer marks, they call them -- on various pieces of the shredded Cessna pulled from the muck. The red does not match red mail bags or other objects known to be on the plane.

-- Investigators also found a small piece of black anodized aluminum embedded in the skin of Preziose's plane. The aluminum is not from the accident airplane.

Those facts led National Transportation Safety Board accident investigator Butch Wilson to conclude the Preziose's Cessna 208B Caravan "collided in-flight with an unknown object."