STROUDSBURG — Four New York City men were given jail sentences Monday in the death of an 18-year-old fraternity pledge during a 2013 hazing ritual in Pennsylvania, with a judge saying she believes they succumbed to “brainwashing” and “indoctrination” that is rampant at fraternities around the nation.

Baruch College freshman Chun “Michael” Deng was blindfolded, forced to wear a heavy backpack and then repeatedly tackled as part of the fraternity’s Crossing Over initiation ceremony. He was knocked unconscious and later died at a hospital.

Police charged 37 people with crimes ranging from aggravated assault to hazing to third-degree murder.

“Not one person out of 37 picked up a telephone and called an ambulance. I cannot wrap my head around it,” Monroe County President Judge Margherita Patti-Worthington said. “So there’s something greater going on here, and I think it’s probably really prevalent. We see across the country these issues in fraternities.”

The four defendants sentenced Monday, Kenny Kwan, Charles Lai, Raymond Lam and Sheldon Wong, pleaded guilty to voluntary manslaughter, hindering apprehension and other charges.

Kwan got 12 to 24 months in county jail. Lam and Wong were sentenced to 10 to 24 months each. Lai, who spent 342 days in jail after he was unable to make bail, was sentenced to time served.

All four defendants apologized, a few of them tearfully.

Lam was the most emotional, saying he has been consumed by guilt. He said he has attempted to kill himself.

“The guilt will never go away, and I think about Mr. Deng every day,” he said.

In a statement to the court, Deng’s mother wrote about the anguish of losing her only son and demanded a sentence that would send a message about hazing.

“This punishment should forever remind them of the pain and grief we will carry for the rest of our lives as the result of their misconduct,” Deng wrote. “It is also our hope that the punishment may also save lives by sending a clear message to other fraternities and their members that the outrageous tradition of hazing will no longer be tolerated and must be ended once and for all.”

Earlier Monday, the Pi Delta Psi fraternity was banned from Pennsylvania for 10 years and was ordered to pay a fine of more than $110,000 for its role in Deng’s death.

The judge and a prosecutor slammed Pi Delta Psi for calling itself a victim of rogue fraternity members, saying the fraternity tolerated and even encouraged hazing for years.

“It’s the epitome of a lack of acceptance of responsibility. It’s their rituals and functions that led us here today,” Monroe County Assistant District Attorney Kim Metzger said in court.

Pi Delta Psi has 25 chapters in 11 states, including one at Penn State University that will now have to be disbanded.

In a written statement, Pi Delta Psi, an Asian-American cultural fraternity founded in 1994, said its now-disbanded Baruch College chapter brought “shame and dishonor” to the national fraternity.

Pi Delta Psi’s attorney, Wes Niemoczynski, argued that Pi Delta Psi had developed a “no excuses” hazing policy before Deng’s death but said the policy worked on the “honor system” and proved to be inadequate.

The fraternity’s initiation rituals “involved some physicality, but they certainly did not involve the level of physicality, the level of inhumanity and the depravity of the individuals who are also coming before the court,” he said.

The defendants sentenced Monday faced the most serious charges. Dozens of other defendants have pleaded guilty and have been sentenced to probation.