Liliana Bachs, MD, Senior Medical Officer at the Norwegian Institute of Public Health, et al., wrote in their article "Acute Cardiovascular Fatalities Following Cannabis Use," published by Forensic Science International in 2001:

“Cannabis is generally considered to be a drug with very low toxicity. In this paper, we report six cases where recent cannabis intake was associated with sudden and unexpected death. An acute cardiovascular event was the probable cause of death. In all cases, cannabis intake was documented by blood analysis.”