The term is a noun phrase. The main point of the phrase, and its grammatical core, is the noun "victims."
In this construction, "victims" serves as the head noun, identifying the primary subject. The preceding words, "Patriots Day," form a compound proper noun that functions as a noun adjunct. A noun adjunct is a noun that modifies another noun, functioning like an adjective. Here, "Patriots Day" specifies which group of victims is being discussed, answering the question "Which victims?"
This grammatical structure is crucial because it centers the subject on the people affected. By identifying "victims" as the main point, the focus of any associated content is inherently directed toward the human element and their experiences. The event itself serves as a defining context rather than the central subject of the phrase.
