A coroner's report seems to suggest that two English rugby players who died of a heroin overdose were seeking brown sugar in the wee hours of the morning in Sri Lanka, but accidentally purchased a kind of heroin nicknamed "brown sugar." From The Guardian:
An inquest at Crook coroner's court heard that the two men, who were "not habitual drug users", had taken a substance known locally as "brown sugar", a cheap version of heroin.
The coroner, Crispin Oliver, said the men purchased the drug on the way home from the nightclub. He said: "They had no prior knowledge of this substance. They would not have known that it was heroin.
"I am satisfied that these were not drug users, I think this was a one-off occasion, it was certainly a mistake and it was certainly an accident."
Crispin added: "I hope this serves as a warning to people when they travel to far parts of the world that they have to be very careful about what they are encouraged to purchase and take."