What to know the mysterious deaths in New Mexico linked to unknown substance

MOUNTAINAIR, N.M. — Investigators in New Mexico are trying to identify a mysterious substance that may have contributed to the deaths of three people and led to more than a dozen first responders being briefly quarantined.

Two people remained in a hospital Thursday, including a person who was found unresponsive in a home where the three died east of Albuquerque, in the rural town of Mountainair.

Authorities went to the home Wednesday after being called about a suspected drug overdose.

Some first responders began coughing, vomiting and experiencing dizziness, authorities said. As a result, medical workers checked nearly two dozen people who may have come into contact with the substance, the University of New Mexico Hospital said.

It was not clear what the substance was, how the people in the home died, what caused some first responders to become sick or exactly how many experienced symptoms. Autopsies will be conducted and authorities said they were testing to determine what substances were in the home.

Here’s what to know about deaths and the investigation.

First responders were decontaminated

Antonette Alguire, a volunteer firefighter in Mountainair, said Wednesday that she saw some EMTs and firefighters coughing, and vomiting after they were outside the house.

Medical workers decontaminated nearly two dozen people, most of them first responders, the University of New Mexico Hospital said. Most of the people had no symptoms, hospital officials said.

Three people were admitted to the hospital Wednesday. One — an emergency medical services official — has since been released, the mayor of Mountainair said Thursday.

Audio reveals some at the home weren't breathing

Audio archives from the Torrance County Fire Dispatch channel on the site Broadcastify reveal that dispatchers went to the home Wednesday morning, responding to a report of a 60-year-old man who was unconscious but breathing. It was unclear who had made the report.

Within minutes, a dispatcher is heard saying there were three people at the home and two might not be breathing. Then came a call for naloxone, the opioid-overdose antidote.

One person was revived using naloxone, which only reverses overdoses in people who have opiates in their systems, Torrance County Undersheriff Stephanie Reynolds said.

Less than an hour after the initial call, the dispatch center relays that there have been multiple exposures, but there’s no clarity about what substance they were exposed to at the house.

Drugs were found in New Mexico home

Mountainair Mayor Peter Nieto said he spotted drugs at the home, but did not say what type of drugs.

He dismissed carbon monoxide or natural gas exposure as possible causes for the health issues that the first responders experienced.

New Mexico State Police spokesperson Wilson Silver said there was no threat to the public and that investigators do not believe the mysterious substance was airborne.

New Mexico has a high number of overdoses

New Mexico had the fourth-highest rate of drug overdose deaths of any U.S. state in 2024, with 775 deaths, according to the most recent data available by the Centers for Disease Control and Prevention.

Residents around Mountainair, a town with less than 1,000 people, have voiced frustration about drug use in the community and elsewhere.

The mayor posted on social media that the town’s law enforcement officers and first responders work daily to protect the community and respond to difficult situations.