Police found three American travelers dead in a Mexico City Airbnb. Having visited at the end of October, they traveled to celebrate Dia de los Muertos, on November 1 and 2.

The bodies of Kandace Florence and Jordan Marshall, both 28, and Courtez Hall, 33, were discovered inside the Mexico City vacation rental. After an autopsy was done on the bodies, local reports cited by Bloomberg confirmed that the cause of death was Carbon Monoxide poisoning.

Florence was reportedly speaking to her boyfriend on the phone when she said that she felt unwell and that something wasn’t right. During their conversation, the call was cut short, which prompted him to reach out to the Airbnb host for a welfare check.

Police officers arrived at the Airbnb and found a strong smell of gas. Officers found everyone dead on arrival.

Currently, authorities in Mexico City are investigating the tragic incident.

The families have spoken out about the pain experienced upon learning the news. At first, there was no information about the cause of death, which made things even more difficult for the families.

Courtez Hall’s mother Ceola Hall told New Orleans NBC affiliate WDSU, “I would hate to see any parents go through what I went through with my son. I didn’t expect to hear this about my son. No one expects that.”

According to PEOPLE reports, they reached out to Airbnb for comment but did not immediately hear back.

On two occasions, guests have died from Carbon Monoxide poisoning while staying at a Sandals resort in the Bahamas. The deaths happened at the same hotel in May and again in August.

Related: U.S. Tourist Found Dead In Same Sandals Resort In The Bahamas Where 3 Died In May