Well, they almost surely died of cardiac arrest. There are only 5 things outside of trauma that can kill you fairly quickly. Cardiac arrest, stroke, aneurism, embolism, anaphylactic shock are the 5 as far as I know. The question is what caused or induced it if it was cardiac arrest. I would suspect a murder suicide or suicide pact. The chemical I mentioned when this thread first started has been in use by archery hunters to quickly kill deer no matter where they're hit. The name of the compound is succinycholine also known as Anectine and if it is obtainable by hunters it wouldn't be hard to get. These were well educated people and they would have been able to research drugs. This stuff breaks down and is almost undetectable and a very small needle mark would be hard to find. I'm not familiar enough with natural release of poison sulfide gas to know if that theory holds water. Dying from heat or dehydration I guess is possible but doesn't sound likely. I could be very wrong on this and I sure don't have all the information.
I believe succinycholine,known to archers as SCC is still legal for hunting in Mississippi. Google" archery pods" and there should be lots of info.
