Lee, 21, was taken to Hahnemann University Hospital, where he died after collapsing at the finish line, according to Penn Vice President for Public Safety Maureen Rush.
Though no official cause of death has been determined, Philadelphia Police spokesperson Jillian Russell told The Philadelphia Inquirer that Lee was pronounced dead at the hospital due to an apparent heart attack.
Lee’s roommate in Harrison College House, College junior Scott Lee — who has no relation to Jeffrey — said he received a phone call at about 11 a.m. Sunday from Harrison College House Dean Frank Pellicone. Scott and another friend rushed to a police station where the death was confirmed.
Around 50 students gathered in Harrison on Sunday afternoon to mourn for Lee. “We were just praying together. There were people holding hands, just sitting together,” Engineering sophomore Jenny Kim said.
The informal gathering was hosted by the Renewal College Fellowship, the college ministry of Renewal Presbyterian Church, of which Lee was a member. A group of students also plan to gather at Meyerson Hall at 10 p.m. Sunday to pray and share memories of Lee.
“We grieve that such a young and promising life has been taken from us so suddenly,” Penn President Amy Gutmann said in a statement. “At times like these we must come together as a community to mourn our loss and support the loved ones of Jeffrey Lee and one another.”
Lee, a Cerritos, Calif., native, leaves behind a community where he was loved by his peers. Many agree that he was kind and sincere and are left in shock by the news.
“He created a warm, welcoming community at Penn with the student groups he’s in and the friends he has made,” Scott said.
Lee was a board member of the Residential Advisory Board and numerous student fellowship groups, as well as an anatomy teaching assistant and a member of Alpha Iota Gamma, the professional healthcare fraternity.
“We all grieved together and were in each other’s company. That’s something he would have really appreciated,” Scott said. “He appreciated little things like friendship, family and love.”
“The most important thing is to take care of each other now,” he added.
Wharton junior and RCF member Erica Jang described Lee as “a big brother to me in a lot of ways.”

“I could always confide in him. We would always have fun and he always brought a smile to my face. He is one of the sweetest and most genuine guys anyone can ever meet,” she said.
Lee was “perfectly poised to have a good life,” Scott added. Lee, a Dean’s List scholar, had planned to work at Microsoft in California after graduation to be near his family.
For Engineering and Wharton junior Luben Li, Lee was one of the first people he ever met on campus. “I was talking to him just yesterday. I found out he was running the half marathon, and I wanted to encourage him,” he said.
“I’m kind of in shock now. It’s very surreal,” he added.
Lee completed the half marathon in just under two hours before collapsing at the finish line near the Philadelphia Museum of Art at 22nd Street and Benjamin Franklin Parkway.
The university will host a support session Monday at 8 p.m. in the Ben Franklin Room of Houston Hall. Students in need of extra support can visit Counseling and Psychological Services, the University Chaplain’s Office and the Vice Provost for University Life.
Another marathon runner, a 40-year-old man unaffiliated with the university, also died at Hahnemann after collapsing.
The Philadelphia Half Marathon is a companion race to the annual Philadelphia Marathon. The races attracted about 25,000 participants.