'Microburst' may have caused Pan Am crash

A weather phenomenon known as a ''microburst'' and associated with thunderstorms could have caused the crash of a Pan American jet in a New Orleans suburb July 9, said meteorologist Dr. Tetsuya Fujita, who discovered the phenomenon in 1977.

Dr. Fujita described a microburst as a sudden downdraft that usually lasts no more than five minutes and often occurs in hot weather when rain quickly evaporates into the air from heated ground. Dr. Fujita, in a three-month study completed Aug. 15, says most microbursts, which occur beneath innocent-looking clouds, cannot be predicted.