BELLEFONTE, Pa. — Eighteen Pennsylvania State University students and their fraternity were charged Friday in one of the largest hazing prosecutions in the nation’s history, sending a chill through the campus in nearby State College as it was about to begin commencement festivities.

Eight students face involuntary manslaughter charges in connection with the death of Tim Piazza, 19, who suffered fatal injuries when he fell down a set of stairs during a Beta Theta Pi pledge party in February.

Flanked by Piazza’s parents and a blown-up portrait of the sophomore engineering major, Centre County District Attorney Stacy Parks Miller accused fraternity members of putting Piazza through a booze-fueled hazing ritual and failing to call for help once it was clear he was seriously injured.

With his arm wrapped around his wife, Piazza’s father, Jim, choked back tears.

“This did not have to happen,” he said. “No parents should have to deal with this.”

The charges were the result of a months-long grand jury investigation and served as an indictment of the Greek system at Penn State.

“The Penn State Greek community nurtured an environment so permissive of excessive drinking and hazing,” the presentment said, “that it emboldened its members to repeatedly act with reckless disregard to human life.”

The panel’s presentment described a ritual known as “the gauntlet” in which Beta Theta Pi pledges were required to stop at various stations, where they guzzled vodka, shotgunned beers, drank from wine bags, and played multiple rounds of beer pong.

Those charged with involuntary manslaughter also face felony charges of aggravated assault, which could result in prison terms, as well as other charges.

Ten other members of Beta Theta Pi face lesser charges, including hazing, furnishing alcohol to minors, reckless endangerment and tampering with evidence.