A Northern Arizona University student who drank an excessive amount of vodka at a fraternity house party died of alcohol poisoning, an autopsy released Monday shows.

Colin Daniel Martinez, 18, was found unresponsive Jan. 31 and couldn’t be resuscitated, the report said. His blood-alcohol level was 0.425% — more than five times the state’s legal limit for driving and an amount generally considered to be fatal.

According to the Flagstaff Police Department, bystanders in the home had already started to perform CPR when officers arrived, and they continued to attempt life-saving measures until paramedics joined them. The student was pronounced dead at the scene despite their efforts.

Three leaders from the Delta Tau Delta fraternity face charges in Martinez’s death: Carter Eslick, 20, the chapter’s new member educator; Ryan Creech, 20, its vice president; and Riley Cass, 20, its treasurer.

The Coconino County Attorney’s Office said Monday it is reviewing the case to determine whether formal charges are appropriate against the three leaders, who were 20 at the time. The three were arrested on suspicion of hazing.

Martinez was among four people who were candidates for the fraternity and shared two bottles of vodka to ensure they vomited, according to court documents released last month. Some witnesses said the bottles might have been diluted with water.

Witnesses reported readjusting his sleeping position, checking his pulse and breathing, and looking up symptoms of alcohol poisoning throughout the night, the documents said.

After Martinez died, the university suspended the fraternity. The national organization later voted to shutter the NAU chapter.

Northern Arizona University said in a statement released after the incident that the school was “mourning the tragic death of a student” and pledged to support the police investigation into the three facing charges.

“We want to be clear: The safety and well-being of our students remain our highest priorities,” the university said. “Violence hazing or any other behavior that endangers others has no place at NAU. The university has robust hazing prevention training and requirements, and has high standards for the conduct of all NAU-associated organizations and individual students.”

Delta Tau Delta International also responded to the student’s death in a statement last month, CBS affiliate KPHO-TV reported. 

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

The fraternity said it “has maintained strong policies barring hazing” since its founding and “vigorously supports the implementation of anti-hazing legislation” in Arizona and federally.