(KTLA) - A cause of death has been determined for three young women from the United States found dead in their hotel room at a resort in San Pedro, Belize, late last month, NBC News reported.   The trio were found dead on Feb. 22 in a room at the Royal Kahal Beach Resort after housekeepers repor ted to management that there had been no answer to knocks at the door for a second consecutive day.   Mexican Mafia associates found guilty of murdering federal inmate Investigators in Belize reported finding the bodies of the women, identified as 26-year-old Wafae El Arar, 24-year-old Imane Mallah and 23-year-old Kaoutar Naqqad, in the room with alcohol, vomit and “gummies” present.   Autopsy reports later found that none of the women had any illicit substances in their systems.   On Feb. 26, Belize Fire Chief Colin Gillet told a Belizean television outlet that carbon monoxide poisoning had not been an issue in the deaths. However, the resort was temporarily shuttered, and a second round of testing was ordered, according to NBC News.   Shops line a street in San Pedro on Ambergris Caye, Belize. (Getty) On March 27, the executive director of Belize’s National Forensic Science Services reported to local news outlets that all three women died from lethal levels of carbon monoxide in their systems.  The resort, meanwhile, had already reopened on March 19, saying in a statement that “all possible steps” had been taken to ensure the safety of its guests and that there was “no further indication of dangerous levels of carbon monoxide in any of the units,” NBC reported.   Patrick M. Keefe Jr., mayor of Revere, Massachusetts, where the young women are from, described the trio as “daughters, friends and contributors to our city,” NBC noted in earlier reporting on the incident.   Family members of the women have reportedly been concerned with the integrity of the investigation. The Massachusetts chief medical examiner’s office plans to run its own tests to determine the manner and cause of death.   ...read more read less