FAIRFIELD, Conn. (CBSNewYork/AP) — A 20-year-old college student whose father was killed in the Sept. 11 attacks has died after choking during a pancake-eating contest.

Sacred Heart University student Caitlin Nelson died Sunday, three days after participating at the contest during a fraternities and sororities event at the Catholic school in Fairfield, Connecticut, police said.

Nelson appeared on CBS2 in 2005 talking about her father and hero James Nelson — a Port Authority of New York and New Jersey police officer killed in the line of duty in the Sept. 11 attacks. The 40-year-old was killed while trying to rescue people trapped in the World Trade Center.

Fairfield police Lt. Bob Kalamaras said the Sacred Heart junior ate about four of five pancakes when she started choking.

Nursing students and first responders performed lifesaving measures on Nelson and she was taken to an area hospital, where she initially was in critical but stable condition, Fairfield police said. She was later transported to New York-Presbyterian/Columbia University Medical Center, where she died.

“It’s a tragic event that started out as something fun,” Kalamaras said.”It was just a tragic accident.”

Several thousand people gathered on the Sacred Heart campus Sunday night to remember Nelson, a member of the Kappa Delta sorority, and share their grief. A Mass dedicated to her was followed by an impromptu candlelight vigil.

“The whole mood is pretty somber on campus right now,” sophomore Kevin Carlson said Monday.

“Our thoughts and prayers are with the family of Caitlin Nelson and the entire @sacredheartuniv community tonight,” a tweet from the Diocese of Bridgeport read.

Our thoughts and prayers are with the family of Caitlin Nelson and the entire @sacredheartuniv community tonight. — Bridgeport Diocese (@Diobpt) April 3, 2017

“I wish to convey my deepest sympathies to Caitlin’s family, friends, and to the Sacred Heart community,” Diocese of Bridgeport Bishop Frank J. Caggiano said in a statement.

I wish to convey my deepest sympathies to Caitlin’s family, friends, and to the Sacred Heart community. pic.twitter.com/b9QTzHhL17 — Bishop Caggiano (@BishopCaggiano) April 3, 2017

School officials said counseling services were being provided.

“The SHU community is mourning today,” the school said in a statement Monday. “We ask that during this time you give Caitlin’s family and the members of the SHU community privacy while they grieve.”

Students were still trying to make sense of the heartbreaking tragedy on Monday.

“Something like that, that’s probably the last thing you’d expect,” Carlson said. “Really sad to hear about it.”

According to her LinkedIn page, Caitlin was certified in youth mental health first aid and volunteered at the Resiliency Center of Newtown, a nonprofit group that provides free counseling and other services to people affected by the 2012 shooting at Sandy Hook Elementary School that killed 20 children and six educators.

Nelson was majoring in social work and was set to graduate in 2018. She was from Clark, New Jersey, where there’s a baseball field was dedicated in memory of her father in 2002.

Funeral services have not been announced.

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)