In a tragedy for one community and possibly a dark historical landmark for marijuana, an 11-month-old boy died from a heart condition that doctors found was likely caused by cannabis ingestion. If they’re right, it may be the first fatality caused by marijuana ingestion on record in the country.

The boy’s death was reported over a year ago in a study of emergency room visits to Colorado hospitals by children exposed to cannabis. At the time, doctors did not know if the 11-year-old’s death was caused by exposure to marijuana, only that he had been admitted to the hospital with a severe heart condition and showed THC in his system.

But this year a new case report from two Denver area doctors found more correlation between the boy’s marijuana exposure and the myocarditis (inflammation of the heart muscle) which caused his death.

“As of this writing, this is the first reported pediatric death associated with cannabis exposure,” wrote Dr. Christopher Hoyte and Dr. Thomas Nappe, both of the Rocky Mountain Poison and Drug Center, in their paper published in an online section of the Western Journal of Emergency Medicine and reported on recently by The Denver Post.

Even Hoyte and Nappe aren’t sure what to make of their discovery. In their report, the official cause of death for the child is listed as myocarditis, not an overdose of marijuana. They’re also unsure how the infant could have ingested so much THC.

The level of the cannabinoid in his system indicates more than just second hand exposure, they say. Though one parent had admitted to possessing cannabis while living with the boy in a motel room, it is unclear why or how they administered cannabis to the child.

Nor are the doctors certain exactly how much THC the boy ingested or when it happened, though they guess it was two to six days before he was admitted to the hospital with a rapid heart beat. They also note that it is slightly possible the myocarditis had developed before he ingested cannabis, but that is neither proven nor disproven by their test results.

“In states where cannabis is legalized,” the report reads, “it is important that physicians not only counsel parents on preventing exposure to cannabis, but to also consider cannabis toxicity in unexplained pediatric myocarditis and cardiac deaths.”

Photo via Flickr user KOMUnews