Before his mysterious disappearance captured national attention, Don Wiley's award-winning career was defined by his extraordinary research in infectious diseases and the immune system.

Memphis, Tenn. [01.15.02] -- One of the nation's most prominent scientists, Don Wiley built an award-winning career as a leader in the fight against infectious diseases like AIDS and Ebola. The Tufts graduate's research was advancing the study of the human immune system by leaps and bounds and was regularly described as Nobel-worthy.

   But his tragic death in November cut his work short, and left the nation's scientific community mourning Wiley's loss.

   "He was delightful, intelligent, articulate, humorous --a good colleague," Stephen Sallan -- chief of staff at the Dana-Farber Cancer Institute -- told The Boston Globe. "He was a very warm person and a gifted scientist. He is someone who we'll miss very much. He made many contributions and he had many more to make."

   A biologist at Harvard, Wiley, 57, was reported missing on Nov. 16, after he left a conference in Memphis. His sudden disappearance drew national and international attention as investigators looked for clues to explain the case. Even the FBI kept tabs on the investigation.

   This week, after a two-month investigation, the Shelby County Medical Examiner declared Wiley's death an accident. According to the report, the scientist drowned after accidentally falling into the Mississippi River.

   "[Dr. O.C.] Smith said in his coroner's report that the fall followed a minor motor vehicle accident on the [Hernando DeSoto] bridge," reported the Associated Press.

   The loss sent shock waves across the nation's scientific community, in which Wiley was a prominent figure. Many considered the 1966 Tufts graduate to be the nation's top authority on infectious diseases and their impact on the human immune system.

   Jeremy Knowles -- a dean and colleague at Harvard, where Wiley worked -- described the researcher's death as a "tragedy for science."

   "Don Wiley was a generous, imaginative, and questing scientist, whose work on viruses and on the nature of the immune response to infectious agents was truly illuminating," Knowles said in a statement. "His research contributions were both important and transforming, and his collaborative search for a better understanding inspired students and colleagues in many scientific disciplines."

   An expert on the structure of viruses and proteins in the immune system, the Tufts graduate repeatedly earned prestigious acclaim for his research throughout his career.

   Among the recent honors, Wiley and a colleague were awarded the Japan Prize in 1999 for their work -- Japan's top scientific honor reserved for outstanding original research.

   As part of his research, Wiley extensively studied AIDS, Ebola, herpes simplex and influenza.

   "[The Tufts graduate] was one of the nation's foremost experts on the way viruses become infectious diseases," reported the Globe.

   Wiley and his colleagues hoped his research would lead to new ways to combat the diseases.

   Born October 21, 1944 in Akron, OH, Wiley grew up in Pennsylvania and New Jersey. He received his undergraduate degree in physics from Tufts University in 1966 and his doctoral degree in biophysics from Harvard in 1971.

   He is survived by his wife Katrin and their two children, as well as two children from a previous marriage.

Images courtesy of Harvard University