Recent evidence indicates that World Trade Center Responders (WTCRs) are apparently at increased risk for a clinical syndrome that includes PTSD (posttraumatic stress disorder) and MCI (mild cognitive impairment). The association of these behavioral and cognitive symptoms was first described by Bromet, Luft, Clouston, and colleagues. No autopsy characterization of the syndrome has yet emerged, though biofluid and neuroimaging biomarker data support features of (1) progressive behavioral and cognitive dysfunction, (2) proteinopathy involving the appearance of neurodegeneration-related molecules in the peripheral circulation, and (3) a substantial regional loss of brain volume. Inciting factors such as inhalation of neurotoxins and/or psychological stressors (or a combination of both) have been proposed as contributory to the pathogenesis, but no definitive etiologic agent has been identified. In general, the subpopulation of WTCRs who developed PTSD and MCI were those with documentable extended exposure to the central feature of “Ground Zero” known as “the pile”, and those who developed MCI were primarily a subgroup of those who had developed PTSD. Multiomic studies are underway to determine whether this subgroup might be enriched for genetic, genomic, and/or proteomic features that might have predisposed them to pathological responses to stress, environmental toxins, or both. In 2017, we had occasion to evaluate “E.T.”; at that time, a 57-year-old bilingual (English and Spanish speaking) right-handed WTCR was referred to an urban medical center dementia specialty clinic for assessment of his cognitive and behavioral functioning. While early-onset dementia can occur sporadically, the proximity of E.T. to “the pile” at “Ground Zero”, and the course of E.T.’s illness raise the possibility that WTC-related cognitive-behavioral syndromes may progress well beyond the stage of MCI to that of moderate dementia (and beyond) and that this progression may occur in the absence of full-blown PTSD.