In an incident at a house in the town of Mountainair, New Mexico, three people exposed to an unknown substance died. Police and medical teams called to the scene found four people unconscious; three died at the scene. The 18 first responders involved in the incident also began showing symptoms such as nausea and dizziness after exposure to the substance. These individuals and the fourth person in the house were taken to the University of New Mexico Hospital, quarantined, and are under observation. The condition of two medical personnel remains serious. Mountainair Mayor Peter Nieto stated that the exact cause of the incident is not yet known, but based on current information, narcotic substances are a possible factor. Albuquerque Fire Department's hazmat teams continue their work to determine what the substance is. Authorities indicated that there is no threat to the public and that the scene has been secured within a safety perimeter. It was also stated that the situation is not related to carbon monoxide or natural gas. The investigation into the incident is ongoing.