NEW YORK (CBSNewYork/AP) — Pennsylvania prosecutors are dropping all assault charges against members of a now-closed Penn State fraternity in the hazing death of a pledge, sparing defendants the most serious allegations any had faced.

The attorney general’s office announced Thursday that it will continue to pursue involuntary manslaughter charges against four former members of Beta Theta Pi in the February 2017 death of 19-year-old pledge Tim Piazza of Lebanon, New Jersey. But those don’t carry the lengthy prison sentences that some of the assault charges did.

The state is now handling the case on referral from a new county district attorney.

A judge had thrown out the most serious charges in September but the county prosecutor at the time refiled them, including eight felony counts of aggravated assault.

Prosecutors are still reviewing the case, which involves 26 defendants.

“Timothy Piazza’s death was a tragedy. When any parent sends their son off to college to get an education, they don’t expect him to be found at the bottom of the basement steps of a fraternity house after a night of hazing, unconscious and fatally injured,” Attorney General Josh Shapiro said in a statement Thursday. “We will seek justice for the Piazza family. My office is committed to holding every responsible individual accountable for their actions, consistent with the law and the evidence in this case.”

Authorities say Piazza, who died while pledging the fraternity on Feb. 2, 2017, was given at least 18 drinks inside of 90 minutes.

Piazza tumbled down a flight of stairs that night and fell several other times, injuring his head, according to the district attorney.

He was found unconscious in the basement the next day, but it was another 40 minutes after that before an ambulance was called, authorities said.

Piazza had a fractured skull, shattered spleen and other injuries. His blood alcohol was estimated at several times the legal driving limit. He died on Feb. 4 as a result of a traumatic brain injury.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)