The Alpha Sigma Phi fraternity has been kicked off the campus of the University of Arizona for allegedly hazing pledges by blindfolding them and forcing them to drink alcohol.

In the incident, one pledge reportedly was injured after being shoved into a pillar at the off-campus fraternity house and had to be hospitalized.

UA police have arrested a student, Cody Ward, 19, in connection with the assault and said the investigation continues.

UA officials said they also received reports that fraternity members threatened to retaliate against anyone who reported the incident.

In a letter to the fraternity, the Dean of Students Office said they talked with witnesses who feared retaliation from fraternity members. "A witness was allegedly told by members of the fraternity the night of the assault that 'we kill rats.' "

Here's how the incident unfolded, according to the UA's investigation:

The fraternity held an event on March 23 at the fraternity house intended to bond members and pledges through activities such as completing puzzles.

Pledges were blindfolded, lined up and walked down a hallway. The pledges were led into a dark room where music blared and they were made to drink alcohol, witnesses told UA officials during the investigation. They had to assemble puzzles in groups of three.

One pledge was shoved into a pillar as he made his way down the hall. He was later seen hunched over, complaining of stomach pains and was taken to the hospital. The UA investigation said the student required "long-term hospitalization."

The fraternity had been on interim loss of recognition since March 31 while UA administrators and police investigate.

UA officials announced Tuesday they pulled university recognitionof the local chapter for the next four years, through May 31, 2021. Loss of recognition means the fraternity cannot conduct any activity on campus, including recruiting members or holding meetings. The fraternity must reapply for recognition after the four-year penalty.

Read a copy of the letter here.

"The University of Arizona has no tolerance for behavior that hurts students or puts them at risk," UA Dean of Students Kendal Washington White said. "The serious nature of the assault allegation warranted the university's decisive action."

A representative of the local chapter could not be reached for comment. The chapter has until May 25 to appeal the university's decision, if it chooses.

The UA Police Department declined to release police reports related to the incident, saying its investigation is ongoing.

Alpha Sigma Phi is part of a national fraternity that bills itself as "America's 10th oldest collegiate fraternity," founded at Yale University in 1845. It also has local chapters in Arizona at Arizona State and Northern Arizona University, according to its website.

A representative from the national chapter could not be reached for comment Tuesday.

The UA chapter has 204 members and is one of the larger fraternities on campus. The UA disciplined the fraternity in fall 2016 for violating alcohol policy. The fraternity had to give presentations on community respect and alcohol safety to some of its members.

The fraternity was on probation for part of the 2015-16 year for student code of conduct violations, according to the university. The fraternity was ordered to give a presentation on legal consequences of drug use to 75 percent of its members.

Reach the reporter at 602-444-8072 or anne.ryman@arizonarepublic.com.