The Sigma Alpha Epsilon members who were caught on video this month singing a racist chant learned the lyrics during a fraternity-sponsored cruise four years ago, University of Oklahoma officials revealed Friday. At an afternoon press conference, David Boren, the university’s president, said the fiercely offensive song was formalized in the local SAE chapter over time, and that it was taught as part of the pledging process, Oklahoma’s News 9 reported.

That revelation was among the findings of a two-and-a-half-week investigation by the school’s Office of Student Affairs. Investigators also found evidence that the fraternity members were drinking alcohol on the day they were recorded singing the chant.

The chant was sung by members of the Kappa chapter of SAE, who were on a bus en route to a Founder’s Day event in Oklahoma City. The song was captured on cellphone video and posted to YouTube the next day, where it quickly went viral. In the video, students can be seen singing in part, “There will never be a n----- in SAE.” According to investigators, about two dozen high school students were also on the bus and heard the chant.   

The cruise on which the members originally learned the chant was sponsored by the national SAE organization, according to the investigation. In a memo posted online Friday, investigators said that in the four years since it was brought to the Oklahoma campus, the chant had become “part of the institutionalized culture of the chapter.”

School officials disciplined 25 students as a result of the investigation. Read the full findings here.