A Northern Arizona University student found dead at a fraternity house drank a large amount of vodka during an initiation event and some partygoers suspected he may have had alcohol poisoning, according to court documents released Monday.

Witnesses told police that some people looked up the symptoms of alcohol poisoning online after hearing the 18-year-old snoring loudly around 3 a.m. Saturday, and readjusted his sleeping position and checked his pulse and breathing, the documents said. About six hours later, the student was found unresponsive, police said in the documents laying out the reasons three members of the fraternity were arrested.

People at the Delta Tau Delta house performed CPR on him and the student wasn’t breathing when officers arrived, police said on Saturday. Officers continued life-saving measures until paramedics arrived, but the student, whose name hasn’t been released, died at the scene, police said.

Three 20-year-old leaders in the fraternity — new member educator Carter Eslick, vice president Ryan Creech and treasurer Riley Cass — were arrested on the criminal charge of hazing, police said. Lawyers representing each of them did not immediately return telephone calls seeking comment. Home telephone numbers for the three couldn’t be immediately found.

According to the documents, Cass had put the victim on an air mattress on his side on Friday night and remained near him until around 6 a.m. The student was last heard speaking late Friday and was discovered unresponsive at 8:44 a.m. Saturday, the documents said.

The victim and three others people identified as candidates to join the fraternity passed around and shared two large bottles of vodka to ensure they vomited, the documents said, though some witnesses told investigators they thought the vodka had been diluted with water.

The cause of death is under investigation, said Trish Lees, a spokesperson for the Coconino County Medical Examiner’s Office

The international leader of the fraternity, which is based in Indiana, said the group is encouraging its members to participate in the investigation into the student’s death and is committed to understanding what led to it.

“Our position on hazing is clear: it is the antithesis of brotherhood and a violation of the values of Delta Tau Delta,” fraternity CEO Jack Kreman said in a statement.

The university said the Northern Arizona chapter of the fraternity has been temporarily suspended while the school conducts its own investigation focused on its policies. In a statement, the university said it had robust hazing prevention training and requirements.

“We want to be clear: The safety and well-being of our students remain our highest priorities. Violence, hazing or any other behavior that endangers others has no place at NAU,” it said.