MIAMI (NewsNation) — According to autopsy and toxicology reports, the three U.S. tourists who were found dead earlier this month at a Sandals Resort in the Bahamas died from carbon monoxide poisoning.

Officers were called to the Sandals Resort on the island of Exuma on May 6 after one of the tourists, a man, was found unresponsive in a villa, the Royal Bahamas Police Force said.

Michael Phillips, 68, and Robbie Phillips, 65, both of Maryville, Tennessee, and Vincent Chiarella, 64, of Florida, were all found dead inside neighboring villas at the resort on Great Exuma Island.

Chiarella was traveling with his wife, but the two couples were not traveling together. They all went to a local clinic in the Bahamas after they told hotel staff they were feeling nausea. Then the next day, three of them were found unresponsive in their villas.

Investigators said no foul play was ever suspected.

Chiarella’s wife, Donnis, was flown to a south Florida hospital and is now in stable condition.

Investigators are still working to determine how the victims got carbon monoxide poisoning. Hotel guests allegedly reported smelling a strong odor, and investigators looked into a possible air conditioning or water heater leak. Still, at this point, they have no comment and are only confirming the cause of death. 

Meanwhile, the investigation is ongoing.

Family members have called for independent autopsies and are waiting for private toxicology reports to come back.