As in the movie "The Last Woman On Earth" (60's), could large-scale CO2 poisoning ever occur?

I'd once seen the movie, "The Last Woman On Earth" (a 1960 flick starring Betsy Jones-Moreland, Antony Carbone & Robert Towne). In it, a mysterious "interruption" of the world's oxygen supply killed off all but 3 people on the entire planet (as far as I know - never finished watching it,... show more I'd once seen the movie, "The Last Woman On Earth" (a 1960 flick starring Betsy Jones-Moreland, Antony Carbone & Robert Towne). In it, a mysterious "interruption" of the world's oxygen supply killed off all but 3 people on the entire planet (as far as I know - never finished watching it, so I don't know if other survivors ever turned up). I got to thinking about the carbon dioxide and other gas deposits that are supressed within the ocean floor and which are released on occasion. CO2 sinks, so those in the upper floors of the taller buildings may escape such a fate, but CO2 bubbles up from the ocean floor all the time, sometimes even quickly enough to sink oil rigs and ships. Is it possible that some sort of undiscovered "super-cavern" of compressed CO2 might some day erupt from the ocean floor and cause such a large-scale, world-wide die-off of oxygen-breathing organisms?
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