A Texas couple’s dream getaway to Fiji ended tragically after they fell sick from a mysterious illness.

Authorities with Fiji’s Ministry of Health and Medical Services said in a statement released this weekend that the tourists, David and Michelle Paul, were on vacation when they died from an illness, which remains to be identified.

Officials say the Pauls became sick between May 22 and May 25. Relatives say their loved ones left behind a two-year-old son and David’s daughter, and they thought both parents were in good health condition.

David served in the Air Force and Michelle served as a student-athlete, one family member said.

The relative, Tracey Calanog, told WFAA the couple loved to travel and had been planning to go to the area for a while. Calanog said the children were left home with extended family.

Authorities are continuing to investigate the cause of the couple’s death.

“We appreciate the efforts made thus far by the Fijian authorities and stand ready to provide further assistance, if requested,” the U.S. Embassy in Fiji announced recently.