[null and void]

You can add Dominican Republic to that list. At least three Americans have died there recently from a fast acting mystery disease—healthy one minute, dead a few minutes later.

My guess, and it's just a guess based on very little information...

There is a freon leak in their room. If they smoke, when they draw chlorofluorocarbon contaminated air through the coal on the cigarette, the heat breaks it down to carbon monoxide chloride - COCl₂ - also know as phosgene.

On the battlefield, phosgene caused death by pulmonary edema. Other symptoms include nausea and vomiting...

[Abathar]

"You can add Dominican Republic to that list. At least three Americans have died there recently from a fast acting mystery disease—healthy one minute, dead a few minutes later."

All three were in the same resort, and all three had just opened bottles from the mini bar. The one lady that died while in her husbands arms went in a matter of seconds after taking a drink. She drank, yelled something, went into convolutions and died while he was trying to administer CPR, all in the matter of minutes.

The deaths there were intentional, they had to be.