ITHACA, N.Y. — An Ithaca College student fatally stabbed at Cornell University was attacked while trying to help a fellow student amid a series of fights after a weekend party, his sister said Aug. 29.

Anthony Nazaire, a 19-year-old sophomore from New York City who was majoring in business administration, and his friend were stabbed early Aug. 28 as several hundred people were leaving a fraternity-sponsored party at the Cornell student union, authorities said.

Police haven’t said what touched off the melee.

Kiara Nazaire said she had spoken with her brother’s friend and was told her brother was trying to get him away from a confrontation when their assailant struck.

“He was defending his friend,” she said, fighting back tears outside her family’s apartment. “It wasn’t to fight. He was pulling him away — and the coward just attacked them.”

Nazaire said her brother had been visiting friends at Cornell and had developed an “upstate New York family” there.

She said her family went to Ithaca on Aug. 28 but returned early Aug. 29 with little information from investigators about their progress.

“I know the cops are going to do everything they have to do to make sure Anthony is at peace,” she said. “We know justice is going to be served.”

Police have not named any suspects in the stabbing, which followed an Aug. 27th night night party organized by Omega Psi Phi, a national fraternity of black men, at Willard Straight Hall as part of a series of events under the umbrella of Cornell’s Black Students United group.

Other Say It Loud 2016 events included orientation sessions for incoming black students, ice cream socials, a Labor Day weekend barbecue and a game night.

Investigators said they were interviewing witnesses and believe based on surveillance footage that some captured the killing on video.

Ithaca College President Tom Rochon said Anthony Nazaire graduated from Brooklyn Theatre Arts High School and was a member of the executive board of Brothers4Brothers, an Ithaca College student organization “dedicated to empowering men of color on our campus.”

About 300 people filled a memorial service on campus, where students described Nazaire’s ever-present smile and determination to succeed as an entrepreneur.

Jaylen Young said his friendship with Nazaire began when Nazaire spotted his Brooklyn Nets hat.

“I’ve lost friends to gang violence, drug dealers,” Young said. “He was never like that. He had goals and plans.”

Minutes before Nazaire died, Young had gone to get the car, leaving his friend to wait for him on the corner, he said. “Anthony, I’m so sorry,” he said. “I wish we could have got there a few minutes earlier.”

Rochon described Nazaire’s mother packing up his belongings and driving back to Brooklyn just nine days after helping unpack them in anticipation of the new school year.

After the service, as students hugged and cried, Rochon said he was proud of the anti-violence message that was a recurring theme of the service.

“We have a shared humanity, we have a shared vision of our future lives and we’re going to work on this together,” Rochon said.

Earlier Aug. 29, outside the student union at Cornell, senior Sonya Qamar said the killing was unsettling.

“There’s the typical occasional break-in where a laptop is stolen or someone gets their wallet stolen out of the library, but it’s completely different when it’s someone getting stabbed outside one of your favorite libraries,” she said.

(CAROLYN THOMPSON and MICHAEL BALSAMO)