Last modified: Tuesday, March 14, 2006 12:13 AM EST Two city principals retiring BY RICK FOSTER/SUN CHRONICLE STAFF ATTLEBORO -- Two city elementary school principals are retiring at the end of the year, adding to the number of administrative vacancies facing a new superintendent. Bonnie Bristow, principal of the Hill-Roberts Elementary School, and Lyn Darling, principal of the Hyman Fine Elementary School, will be retiring in June, according to person nel Administrator Marianne McAllis ter. High School Principal Jackie Proulx announced her retirement earlier this year. Both McAllister and Superintendent Joel Lovering are also planning to retire at the end of the school year. Bristow has worked for the school department for 37 years, both as a teacher and school principal. She began her teaching career at the for mer South Attleboro Middle School in 1969 and served as assistant principal there from 1976-1982. She later served as principal of the Studley and Fin berg Schools prior to being appointed Hill-Roberts principal in 1993. Darling, a former grade 1 and 2 teacher, joined the school system in 1984. She taught at both Hyman Fine and Hill Roberts schools before being appointed principal of Hyman Fine in 1998. Lovering said the two principals have made a major contribution to education in Attleboro, both as lead ers in their schools and as a steady ing influence during the school fiscal crisis of 2003-04, which resulted in major cutbacks. `` Attleboro has been very fortunate to have administrators of this caliber,'' he said. `` They will be missed.''