Investigators probing the Monday night crash of American Eagle flight 4184 in northwest Indiana are going down the list of possible causes -- but the most obvious clues don't seem to stand up to scrutiny. Initially, rainy, windy weather along an approach to Chicago was thought to be a possibility, but National Transportation Safety Board Chairman Jim Hall said today that while conditions were far from ideal, "airplanes operate every day in this type of weather." Another possible cause, mechanical failure, is also questionable. The European-manufactured plane was almost brand new. It was registered with federal officials in March and, as of September, only one problem with the plane had been reported -- a broken floor light. The crash was fierce enough to cause most of the plane to disintegrate into pieces small enough to be held by hand. "There's not one body that's intact," said a firefighter at the scene. The flight data and cockpit recorder were both recovered.