The body of 20-year-old Nicholas Barnes was found Saturday. The last time he used his keycard to enter his dorm was on February 7.
Barnes lived in the International House in the 1400 block of East 59th Street.
The Cook County Medical Examiner's said his death was not the result of a suicide, but said autopsy results are inconclusive, pending toxicology results.
A moment of silence as a school community mourns the death of a fellow student.
"Nick, who you might not have known him, but I believe God knows him and he cares for him. He cares for his family, his friends," said student Sean Wang.
Police found the decomposing body of the University of Chicago student in his campus dorm room after others noticed a strange odor in the hallway and alerted authorities.
"While I was going to my friend's room (Saturday) I like smell a foul smell," said student Eva Kenabrew.
The 20-year-old was found face down on the floor of his room, where he lived alone, at the school's International House Residence Hall.
Investigators say Barnes had last used his university keycard to enter the dorm a little before 11 p.m. on February 7.
"I don't understand how the people that live next door, and the people who were responsible for his well-being could have not seen that he has been gone for a week," said International House resident Jordan Ginsburg.
"It's uncomfortable," said resident Ryo Atnei. "I can't believe no one noticed."
University officials informed students about the death by email which reads in part: "University staff are making every effort to understand the circumstances surrounding Nicholas' death. Nicholas was an excellent student, admired by faculty and peers alike."
Barnes was a third-year student from Pittsburgh.
He majored in Germanic studies and studied abroad in the College's Vienna program in fall quarter of 2012.
He was involved with the campus literary publication Sliced Bread.
"Just mostly confused and shocked that this could have been going on since February 7th and we had no idea," said student Madeline Kowalski.
Sunday afternoon, Students remain shocked by the news are still looking for answers.
"It helps us to know the person who died and to talk about why this is important and to get past this," said Nolan Robinson.
University officials said they have been told by the family that there will be a funeral for Barnes in Pittsburgh, where he grew up.
In the meantime, school officials are making counselors available to students as they plan for a campus memorial.