Daniela Dessi (14 May 1957 – 20 August 2016) This soprano crossed my path only once--at the Wiener Staatsoper in 2007 when I saw her in Manon Lescaut. I enjoyed her work, but she was upstaged by the production. She died of cancer.
Johan Botha (19 August 1965 – 8 September 2016) Tenor Johan is another matter. I have seen him sing Otello, beautifully, and Tannhäuser. The latter was a towering experience for me. He died of cancer at 51.
I'm compiling a list of active opera singers, and the number only goes up to 110 so far. I count only those I have heard at least once. This means they are a small family whose deaths we mourn. My favorite death music is here.