Mystery substance in New Mexico home leaves 3 dead, 19 hospitalized: What investigators have revealed

Police rushed to a home in Mountainair for a ‘suspected overdose’ Wednesday

Antonette Alguire, a firefighter with Mountainair's volunteer fire department, helped to give CPR to a woman outside the home and watched as EMTs and firefighters started coughing, vomiting and becoming dizzy at the heliport.

First responders who were called to a home in Mountainair soon began experiencing symptoms of nausea and dizziness after possible exposure to the unknown substance.

Of the four individuals found unresponsive inside the home in Mountainair, a rural community east of Albuquerque, three were pronounced dead.