The family of Abby Lutz, one of two Americans found dead in Mexico on Tuesday, said Thursday that they believe she and her boyfriend died of carbon monoxide poisoning while on vacation.

The couple was found in a hotel room in the El Pescadero community in Mexico. Baja California Peninsula, according to the state attorney in Baja.

The man has not been publicly identified.

Initial forensic examination indicated that the couple died of intoxication from a substance, which authorities are still working to identify.

Lutz’s family said in their GoFundMe campaign for funeral costs that they were told by authorities the couple may have died of carbon monoxide poisoning due to inadequate ventilation.

Abby Lutz.Courtesy of the Lutz family

Lutz’s stepsister, Gabrielle Slate, said the couple felt terribly ill over the weekend and went to the hospital, where they were given intravenous fluids.

«He got really sick on Saturday and they thought it was food poisoning,» Slate said. «She wasn’t getting better, so she was taken to the emergency room, where she got help and she came back to the hotel feeling fine.»

Her family believed the couple was on the mend and enjoying the rest of their vacation until they got a call from the US State Department, stepmother Racquel Lutz said.

«They just thought it was food poisoning,» he said. «They had no idea. None of us thought of that. You know, because you can’t smell carbon monoxide.»

Henar Gil, general manager of Rancho Pescadero, offered his condolences to the family in a statement Thursday.

«The safety of our guests and colleagues is always a top priority,» Gil said. «Local authorities confirmed that there was no evidence of violence related to this isolated incident, and there is no threat to the safety or well-being of guests at this time.»

Gil, who said the hotel would refrain from speculating on the cause of death, referred inquiries to local authorities.

Abby Lutz.
Abby Lutz.Courtesy of the Lutz family

Slate said her half-sister was a frequent traveler and the couple was very familiar with Mexico. The family knew that both Abby Lutz and her boyfriend were savvy travelers and only frequented areas they considered safe.

«I think the hardest part is going to a resort where you think you’re going to be taken care of,» Slate said.

Racquel Lutz said, «It was so absurd and it could have been prevented.»

Carbon monoxide was responsible for two incidents last year in which Americans died from the noxious gas while on vacation.

In May of last year, three tourists — Michael Phillips, 68; Robbie Phillips, 65; and Vincent Chiarella, 64, died of carbon monoxide poisoning at a Sandals resort in the Bahamas.

Months later, in November, a group of Americans staying in an Airbnb rental in Mexico City died the same way. Their families said at the time they were surprised the rental company didn’t require hosts to have working carbon monoxide detectors.

Abby Lutz’s father, Tony Lutz, is devastated, the family said Thursday. She had just made travel plans to visit him for Father’s Day this weekend.

Her stepmother described her as an animal lover who was always excited to give presents at Christmas, making «trinkets» for everyone in her pottery class.

«I always wanted more kids, and I had Abby when Tony and I got married,» she said. «And that was one of the most wonderful parts of having another daughter to share life with.»

Slate said she will remember her sister for her sweetness and her love for her nieces and nephews.

«I don’t think I’ve ever heard her say a bad word about anybody,» Slate said. «She is the happiest and most positive person. She loved everyone around her.»