Investigators in New Mexico are working to identify an unknown substance they say may have contributed to the deaths of three people. Multiple reports describe an incident in which more than a dozen first responders were briefly quarantined as officials assessed potential exposure risks. The Independent reports that some responders develop symptoms including coughing, vomiting and dizziness, prompting medical evaluation and temporary isolation measures. Stuff.co.nz similarly says investigators are trying to determine what the substance is and whether it played a role in the fatalities. Authorities are treating the situation as an active investigation, with the focus on determining the cause of death and identifying the source or composition of the suspected substance. Officials have not publicly confirmed the substance’s identity or provided definitive conclusions about how exposure occurred. Medical and investigative efforts are ongoing as investigators continue analyzing available evidence and monitoring exposed individuals.