chemical , isotopic , geologic , and medical evidence support the hypotheses that ( i ) the bulk of gas released was carbon dioxide that had been stored in the lake 's hypolimnion , ( ii ) the victims exposed to the gas cloud died of carbon dioxide asphyxiation , ( iii ) the carbon dioxide was derived from magmatic sources , and ( iv ) there was no significant , direct volcanic activity involved .
C0004044
asphyxiation
C0007012
carbon dioxide