Casey, from Whitehall Township, near Allentown, was also a dedicated student, active in the honors college and at the student union building, where he worked as a student director, friends said. A trumpet player, he "basically lived in the music building," said Kristin Neel, a 2011 graduate and a member of the school's Sigma Alpha Iota music sorority.
Casey had traveled with other fraternity members to Pennsylvania State University's main campus for a conference last weekend and fell ill on the way home, Wolf said.
By Tuesday afternoon, it was clear something was seriously wrong. By Tuesday night, more than 100 students were filing in and out of Casey's hospital room. They had been informed that it was unlikely he would survive.
"The aura was just not right - we all knew," Wolf said. "There were a lot of tears, a lot of silence."
The school held several candlelight vigils for Casey throughout the week.
"The loss of a student touches everyone on the campus, and I know that Sean and his family will be remembered in our thoughts and prayers in the days ahead," university president Greg Weisenstein said in a statement.
University officials said they were encouraging anyone on campus to seek treatment if they experienced symptoms of meningitis, which include chills, fever, vomiting, a stiff neck, headaches, and a rash.
West Chester students living in residence halls are required to sign a form indicating they have received a meningitis vaccine, university spokeswoman Pamela Sheridan said.
At Penn State, spokeswoman Jill Shockey said students who had come into contact with Casey over the weekend had been identified and given antibiotics.
Bacterial meningitis is not highly contagious but can be spread through direct saliva contact, like kissing or sharing utensils.
Friends said they were struggling with Casey's loss but were comforted by the campus community and Casey's family.
"It's amazing how one young man can bring so many people together. I feel blessed to be part of such a community of people," Neel said.
Contact Aubrey Whelan at 610-313-8112, at firstname.lastname@example.org or on Twitter at @aubreyjwhelan.