Late Monday evening, around 11:41 p.m., emergency responders rushed to a Supermarket in Plaistow, New Hampshire, after multiple 911 calls reported a strong odor and several people inside feeling ill, some needing help to exit the building. Fire crews upon arrival detected alarmingly high levels of carbon monoxide—300 parts per million—near the rear of the store, where a gas-powered pressure washer operated by a third-party cleaning company was suspected as the source of the leak. Of the 14 workers present at the time, four suffered symptoms of CO poisoning ranging from mild to severe and were promptly transported to local emergency rooms for treatment, while the remaining ten were safely evacuated and monitored on site.
In a swift response, firefighters ventilated the entire store, effectively clearing the hazardous gas and eliminating any ongoing threat to workers or the public. The unaffected employees were cleared to resume their shifts shortly after, and officials confirmed that all four hospitalized individuals are expected to make full recoveries. The incident highlights the dangers of using fuel-burning equipment in enclosed spaces without proper ventilation, underscoring the importance of rapid detection and response to prevent more serious outcomes.