Gas leak may have killed 21 youths in South Africa tavern

Natural gas methane is odorless and colorless.

In the developed parts of the world, a distinctive smell is added using mercaptan (rotten egg smell) so any gas leak is quickly known and people all know to go outside and not cause any sparks or flames. But this breaks down when the leak happens in nature, like from coal mines.

Coal mines in ZA have been found to have huge gas leaks thanks to space science. https://africanews.space/satellite-detects-large-methane-leak-in-south-africas-coal-mining-region/

I guessed CO (carbon monoxide) poisoning in the prior story here. CO is also odorless and colorless. I doubt CO detectors are required in ZA. They are here, on every floor and near any equipment prone to releasing CO. I wasn't able to find any laws/codes mandating CO detectors in ZA. New rules from May 2021 around fire detectors were found which are about the same as most European countries. Those rules required 2 major fires to become the standard. Hopefully, CO detectors will quickly become standard now that 21 people have died.