Ulysses Diaz kneeled in the snow before a white cross with his friend's name written in red across it.

Diaz, 21, a student at Northern Illinois University, came to the makeshift memorial on Friday to remember Catalina Garcia, 20, who died at the hands of a gunman while sitting in her geology class.

"I will always remember the last smile I got from her," said Diaz, with tears in his eyes, recalling a memory of a hug shared at a bus stop not long ago.

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Garcia, one of five victims killed by Stephen Kazmierczak, a former graduate student who took his own life, was known to Diaz as "Cathy."

"Some people are in a better place," Diaz said, adding that "I'm thankful to be alive."

• Students Find Comfort in Faith After Campus Tragedy

George Gaynor is also happy to be alive a day after the gunman entered his classroom.

Gaynor was sitting on the back row in Cole Hall, taking notes about micro-organisms when he looked up at the clock. Five seconds later, the screaming began.

"I couldn't believe what my eyes were seeing," said Gaynor, a geography senior. "I have never heard anything like that in my life."

The gunman continued his rapid-fire shooting spree as Gaynor managed to escape out a back door.

Not too far from the crime scene where Gaynor ran for safety, Jessica Manning came back to campus to remember those lost.

"I wanted to pay tribute to all the victims and their families," said Manning, a freshman, at a vigil set up on a pile of snow with red and white candles, "Go Huskies" banners and bouquets of red flowers.

Manning's roommate was in the classroom at the time of the shooting, running for her life when the gunshots rang out.

"She was really shaken up," Manning said. "She saw the gunman and hit the ground and crawled out."

Four other friends, wearing black and red ribbons pinned to their coats and sweatshirts, joined Manning to leave six candles in honor of the fallen.

While classes are canceled for now, it is unknown how the campus will return to normal.

Murali Krishnamurthi, an industrial engineering professor, teared up at the thought of someone entering his classroom to harm his students.

"Every time the classroom door opens the next few weeks, I'll be apprehensive," Krishnamurthi said. "The last thing I want to see while I am teaching is for any student to be hurt."

Andy Small, a facilities and laboratories manager for the Department of Chemistry and Biochemistry, said he doesn't know how the campus will move forward.

"Our lives have changed," said Small, wearing a red and black Huskies sweater after a morning press conference.

"You have to look at life differently now."