University of Texas-Austin stabbing victim identified ...

University of Texas-Austin student Elissa Garza said she and her friend, Ileanna Guerri, were having lunch, enjoying "a beautiful day" on campus Monday, when a fellow student came into the area and attacked multiple students with a knife, killing one and injuring three others.

"It didn't seem real," Garza said in an interview with ABC News on Monday. "I had never seen so many people's faces in utter terror."

Garza, one of at least 25 students who witnessed the attack, said school officials urged people to go on with their normal schedules until they could gather more information about the situation. She went into her class, which happened to be next to the Gregory gym building, where the stabbing incident occurred, but she said she found it hard to focus on her work.

"I was a little terrified of being in that building, but my teacher was extremely understanding, she let us turn in our assignment and walk out," Garza said. "She knew it was a little uneasy on campus already."

Authorities are still working to figure out the motive behind the attack.

The university said it apprehended the suspect, 21-year-old UT Austin student Kendrex White, who allegedly attacked the students with what appeared to be a large hunting knife and "calmly" walked away, according to police.

White is currently being interrogated by police and has not yet been charged.

One of the victims died at the scene, according to UT Austin police.

Two of the three victims who were seriously injured in the stabbing were released from the hospital on Monday, according to a university statement late Monday. The university didn't provide details on the third surviving victim in the statement.

Guerri, who witnessed the stabbing with Garza, said she’s been thinking about the incident a lot since it happened on Monday afternoon. She fears that a similar incident could happen again.

"It was the middle of the day and this happened ... he was a student," Guerri said in an interview with ABC News on Monday. “It’s hard for me to not worry about that, to not worry that that's going to happen again.”

Other students have expressed similar fears.

“A lot of people have been saying they don’t want to go outside or go back to their dorm. They don’t want to walk to classes tomorrow,” according to University of Texas Austin Freshman Rachel Prichett, who said she was standing in line at a food truck near the gym when she suddenly heard screaming.

She said she was just a few feet away from one of the victims when he was stabbed.

"It is pretty terrifying," Prichett said. "If I had been facing the other away, had my back to that guy, it could have been me that he targeted."

In a letter released late Monday, University of Texas Austin President Gregory Fenves acknowledged that the campus had been gripped by "very understandable” fear in the wake of the attack.

“There is a great deal of fear on campus and in our community,” Fenves said. “That fear is very understandable, especially in light of recent vandalism and threats against students.”

Fenves did not offer details on vandalism or threats mentioned in the letter, but Prichett told ABC News that she was aware of “a couple” of alleged threats on campus.

“There have actually been a couple of other supposed threats that have happened,” Prichett said. “There was a banner up somewhere that said “tuition pays for bombing” or something like that,” she added.

The university said classes and events will resume on Tuesday and it plans to hold a “gathering to honor the victims” in the coming days.

“And I know that it will be a very difficult day for everyone on the Forty Acres, so please, be there for one another,” Fenves said, using a colloquial term that refers to the university as a whole. “[P]lease keep your thoughts and prayers with the victims and their families during this very difficult time.

ABC News' Kevin Pliszak, Bonnie Mclean and Becky Perlow contributed to this report.