* Bus schedules: If the school serves a large, geographically spread-out area, early start times might be necessary to accommodate bus routes and ensure students arrive on time.
* Teacher availability/scheduling constraints: Teacher schedules and other logistical factors within the school might necessitate an earlier start time.
* District-wide policies: Some districts may have a standardized start time for all their schools for logistical reasons.
In short, a 6 a.m. start time is unusual but not unheard of, and it's likely a result of a combination of factors specific to that individual school and district.