[Qiviut]

If I had to guess, I would say something like this happened - waste produces deadly gasses as it decomposes:

Mennonite family die from deadly methane gas in farm manure pit
https://www.dailymail.co.uk/news/article-465971/Mennonite-family-die-deadly-methane-gas-farm-manure-pit.html

Deadly methane gas from a Virginia dairy farm’s manure pit killed five people, including a Mennonite family, in tragic sequence as each tried to save the other.

Emergency workers speculate each of the victims climbed into the pit in a frantic attempt to rescue the others.

“It was a domino effect with one person going in, the second person going after them,” Sheriff Don Farley said.

[Eleutheria5]

Israel is killing Menonites, too?

[zek157]

Yeah. Very sad.

[Ozark Tom]

1. Methane lighter than air—floats away.
2. Decomposition of biological materials produces hydrogen sulfide.