I receive a lot of questions from medical school applicants regarding the “why our school” secondary essay prompt. Although it’s work, the goal is to research each institution and then link your qualities and interests with the school’s.
Be very specific. Look into what makes the institution distinctive, including electives, curriculum, awards, international opportunities, and research.
The mistake I see is that candidates tend to use generalities, a tactic which doesn’t afford the admissions committee members a sense that the applicant is really interested in their institution.
If your interests and accomplishments are linked to the underserved, for example, look into the school’s commitment to that community (a free clinic at which students volunteer, a medical student program to teach sex ed in a struggling high school). Then, in your essay, specifically review your achievements and the school’s associated opportunities.