“The investigators say there is no evidence in the wreckage or on the flight recorders of an in-flight fire or explosion. A plane breaking up in flight, as this one did, might in its last moments produce flashes of fire from engines ripping loose, but the idea that the plane caught fire is a trick of memory, they say.”

http://www.nytimes.com/2002/06/23/weekinreview/ideas-trends-for-air-crash-detectives-seeing-isn-t-believing.html