The Citadel has dismissed a cadet for one academic year and suspended two others for a semester for their role in an incident in which several cadets at the South Carolina school donned white pillowcases for a costumed event that many saw as evocative of the Ku Klux Klan.

The punishment, reported Monday by the Post and Courier, concluded an investigation that began after the Dec. 9 incident was reported to the administration of the public military college. Images of white-hooded cadets circulated at the time on social media.

Those involved said the costumes were not meant as a racial provocation but rather an attempt to dress up as “ghosts of Christmas past,” a reference to the Charles Dickens tale “A Christmas Carol,” while cadets were singing holiday songs.

Citadel President John Rosa, a retired Air Force lieutenant general, said at the time that he found the imagery “offensive and disturbing” and issued eight temporary suspensions while an investigation was under way.

On Monday, the college announced the conclusion of the investigation.

“The investigation found that the cadets did not intend to be offensive,” Rosa said in a statement. “However, I am disappointed some recognized how it could be construed as such but didn’t stop it.”

Fourteen cadets received punishments ranging from on-campus sanctions to dismissal, the college said. A dismissal requires a cadet to spend two semesters away from campus. The dismissed cadet is entitled to apply for re-entry, a Citadel spokesman said. That student and the two who received suspensions were from the upper classes of the cadet corps.

The on-campus sanctions will require marching tours for 11 cadets, a regimented duty in which they carry rifles on their shoulders, said the spokesman.

According to The Citadel, several cadets told their leadership within an hour of the incident that they had seen a small group of freshmen dressed in costumes with white pillowcases on their heads. Word quickly was relayed up the chain of commend.

The investigation found, according to The Citadel:

“A group of freshmen were directed to report to an upper class cadet’s room over a number of nights after Thanksgiving furlough to sing Christmas carols while dressed in costumes.
“This incident occurred on the night before finals week. The freshmen used what they had close at hand, including pillowcases and other uniform items, in an attempt to dress as ‘Ghosts of Christmas Past.’
“At the outset, not all of the freshmen understood that the costumes could be construed by some as offensive in nature. Those who did thought they could easily explain that they were only dressed as ghosts, and said they just needed to complete the skit so they could resume studying.
“The lyrics sheets in the photos were for Christmas songs: ‘It’s the Most Wonderful Time of the Year’; ‘Have a Holly Jolly Christmas’; and ‘Joy to the World.’ There was nothing offensive on the lyrics sheets.”

Rosa said the incident showed “poor judgment” and demonstrated the college must intensify diversity education in daily activities and the curriculum. “The bottom line is that the cadets involved now understand that the costumes could be considered offensive and hurtful to many,” Rosa said.

The Citadel also said Rosa is creating a Task Force on Advancing Diversity and Inclusion, to be led by the college’s Diversity, Equality and Inclusion Council.

The Citadel, founded in 1843, has about 3,600 students. Its first African American cadet was admitted in 1966. Of its 2,763 undergraduates in 2014, 77 percent were white, 8 percent black, 6 percent Hispanic and 3 percent multiracial. Half come from South Carolina and the rest from out of state.