Associate Dean of Student Life Kimberly A. Pacelli, the administrator who helped guide the Office of Student Life while it had no head, will leave Harvard on July 19 to become senior associate dean of student affairs at Bowdoin College.

During her nearly year-long tenure at Harvard, Pacelli had a hand in shepherding the College through a series of crises, including a major city power outage, a hurricane, a blizzard, and the Boston Marathon bombings and their aftermath.

Pacelli first came to Harvard to assume her post at the Office of Student Life in the fall of 2012. Much of Pacelli’s tenure was marked by the absence of a dean of student life, as the post was vacant from last August, when former interim dean Joshua G. McIntosh left Harvard for Johns Hopkins University, until March, when Stephen Lassonde took over the deanship.

In an email Monday announcing Pacelli’s departure to House Masters, resident deans, and college staff, Lassonde and outgoing Dean of the College Evelynn M. Hammonds praised Pacelli for “master[ing] an important and complicated position in the Office of Student Life."

As associate dean, Pacelli has advised the House Renewal project, Harvard’s ambitious plan to renovate its upperclassman Houses. She has also served as chair of the Faculty of Arts and Sciences Safety Committee and has been involved in the emergency management team for the College.

“We're sad to lose her, because she's been such a terrific addition to this office, from what I understand, from the moment she arrived,” Lassonde said in a phone interview Tuesday.

Lassonde said he has been told by colleagues that Pacelli transitioned to Harvard especially quickly when she arrived in the fall. He said Pacelli was “pinch-hitting” while working at the OSL with Associate Dean of Student Life David R. Friedrich in the absence of a dean of student life.

“She really did a great job filling in there,” Lassonde said.