Attolico was an Italian diplomat before and during WWII. He was, among his other titles, Itallian ambassador to Brazil, the Soviet Union, Germany, and finally the Vatican City until his death in 1942. I know he died in 1942, but I don’t know how. Was it the war? Was it natural causes? Does anyone know?
Just looking through Google books, it sort of looks like he died of natural causes. This snippet seems to suggest he was worn out with his labors, and I found another reference to his being on his sick-bed.
According to the book, The Pope At War by David I Kertzer -Penguin Random House, 2022, p. 222: “0n February 9, 1942, …Bernardo Attolico, who had long suffered from heart and liver ills, passed away.”