Jay M. Harris, dean of undergraduate education at Harvard University, addresses evacuated students in Annenberg Hall on Monday, Dec. 16, 2013, after unconfirmed reports of explosives in four campus buildings in Cambridge, Mass. (AP Photo/The Harvard Crimson, Jessica C. Salley)

Photo by: Jessica C. Salley

Jay M. Harris, dean of undergraduate education at Harvard University, addresses evacuated students in Annenberg Hall on Monday, Dec. 16, 2013, after unconfirmed reports of explosives in four campus buildings in Cambridge, Mass. (AP Photo/The Harvard Crimson, Jessica C. Salley)