So here's the answer to the African Mystery I blogged about a little while ago.

Lakes naturally absorb CO2 into them. It's pressurized by the weight of the water and goes down to the bottom of the lake. However, most lakes have seasonal change or at least enough wind to make the CO2 come to the top in a harmless fashion. But when you're at the equator, in an extra deep lake, surrounded by volcanic walls, you don't get much movement.

So over time the CO2 built up in this lake. The weight of the water held it down but there was a huge amount of CO2 underwater. But when a cliff face collapsed into a rock side into the water, the bottom of the lake was upturned. It then shot all the CO2 out in a massive burst (the explosion sound). Since dry ice is just hardened CO2, it naturally became a thick fog. Also since CO2 is heavier than oxygen, any oxygen in it's path was pushed away.

That means that all the victims suffocated.

As for the burns, it was frostbite that got them. Thus why some had it, some didn't, and the clothes weren't effected. For the smell of rotten eggs, gunpowder and sulfur, CO2 in high percentages acts as a sensory hallucinogen. From testing in the army, the most common responses from high CO2 levels was they felt warm and smelled rotten eggs, gunpowder and sulfur.

When the burst happened, it brought a lot of iron up to the surface. With sudden contact with the air, the iron rusted, making the lake orange.

Pretty wild story, huh?

Xidash