Members of the international HIV research community who are heading to Melbourne, Australia, for a huge international AIDS conference beginning this weekend are in a state of shock and grief after hearing reports that a prominent European researcher and at least several other delegates perished when Malaysia Airlines Flight 17 was shot down Thursday over eastern Ukraine.

“The International AIDS Society (IAS) today expresses its sincere sadness at receiving news that a number of colleagues and friends en route to attend the 20th International AIDS Conference taking place in Melbourne, Australia, were on board the Malaysian Airlines MH17 flight that has crashed over Ukraine earlier today,” conference officials said in a statement. “At this incredibly sad and sensitive time the IAS stands with our international family and sends condolences to the loved ones of those who have been lost to this tragedy.”

The identities of the victims have not been confirmed by the airline.

One delegate described the group that had already gathered in Australia as being devastated. About 14,000 delegates are expected at the conference.

AIDS research has been marked by previous aviation disasters. Irving S. Sigal, a molecular biologist who helped develop the drugs used to treat HIV, died in the explosion of Pan Am Flight 103 over Lockerbie, Scotland, in 1988. Ten years later, prominent researchers Jonathan Mann and Mary Lou Clements-Mann died in the crash of Swissair Flight 111 off the coast of Nova Scotia, Canada.

Vice President of Malaysia Airlines Europe Huib Gorter revealed the nationalities of passengers who were on downed Flight MH17, which was carrying 295 people. (Reuters)