Students flood out of Sever Hall Monday after Harvard University received an unconfirmed bomb threat. Harvard University Police Department officers worked with local and federal authorities to investigate the scene. By Tim C. Devine

In Photos: Bomb Threat Shakes the Yard

Harvard police received an unconfirmed bomb threat via email on Monday, prompting an evacuation of four buildings in and around Harvard Yard before it was determined to be unfounded. The Crimson's multimedia staff documents the scene as the investigation unfolded.

By Crimson Multimedia Staff

{textmod size=slideshow header="Students Evacuate" text="After Harvard police receives an unconfirmed bomb threat via email, students evacuate the Science Center and Sever, Emerson, and Thayer Halls, similar to two years ago, when another unfounded bomb threat interrupted the fall finals period in 2013." align=center}

Students stream out of Harvard Yard. Photographer: Michelle M. Ng

Students walk out of Sever Hall. Photographer: Tim C. Devine

Members of the Harvard University Police Department direct people away from Harvard Yard and the Science Center. Photographer: Madeline R. Lear

{textmod size=slideshow header="Harvard Yard Closes" text="Law enforcement officials restrict access to the four buildings, the Science Center Plaza, and Harvard Yard. Students gather in Annenberg Hall, open for those who cannot return to their rooms." align=center}

Harvard Yard lies empty. Photographer: Matthew W. DeShaw

Khurana Addresses Students - Dean of the College Rakesh Khurana speaks with first-year students in Annenberg Hall, which stayed open following reports of a bomb threat on campus.

Dean of the College Rakesh Khurana speak with first-year students in Annenberg Hall, which stayed open. Photographer: Madeline R. Lear By Madeline R. Lear

Access to the Science Center Plaza is restricted. Photographer: Lauren A. Sierra

Police at Memorial Hall -

Members of the Cambridge Police Department stand outside Memorial Hall. Photographer: Lauren A. Sierra By Lauren A. Sierra

{textmod size=slideshow header="Police Search" text="After students and faculty evacuate the affected buildings, law enforcement officials spend the next several hours searching them. They eventually clear all four and determine that they pose no threat." align=center}

Special Response Team at Sever - Members of the Cambridge Police Special Response Team (SRT) converge outside of Sever Hall Monday afternoon. The building was one of many evacuated during the the bomb threat.

Members of the Cambridge Police Special Response Team (SRT) converge outside of Sever Hall. Photographer: Matthew W. DeShaw

Firefighters stand outside Sever Hall. Photographer: Lauren A. Sierra