• Gunman opened fire at Northern Illinois University's Cole Hall killing five people and wounding 16 others before taking his own life
• Campus on lockdown until death of the gunman was confirmed
• The gunman identified as Steven Kazmierczak, a 27-year-old graduate student at the University of Illinois and former NIU graduate student
• NIU classes cancelled until Monday

Haley Burton stayed in her apartment the whole weekend. She wasn't studying for an important exam on Monday. She wasn't feeling sick. But after last week's shooting, the Northern Illinois University junior did not feel safe going outside.

Last Thursday, Burton skipped class to leave campus at 2:45 p.m. so she could catch a train to Chicago to spend Valentine's Day with her boyfriend. Students are usually discouraged from skipping class, but it may have been one of the best decisions of Burton's college career as it helped her escape the chaos and tragedy that followed.

Had Burton attended class, she would have been in a building across the street from Cole Hall, where the tragedy took place.

Around 3 p.m. a man dressed in black entered Cole Hall with a shotgun and two handguns, and opened fire in a geology class, killing five people and wounding 16 before taking his own life, according to the Associated Press.

"I had no idea that anything was happening until my friends started texting me while I was on the train," Burton said.

She said she received several text messages asking if she had heard about a shooting on campus. But a phone call from her mom at about 4 p.m. let her know what was happening on the campus she had left just an hour earlier.

Burton said she immediately tried contacting her friends, but she had trouble because cell phone towers were busy.

"There was a little bit of panic for a few hours because I couldn't get a hold of anybody," she said.

Back on campus, Heather Morrissey, a senior at NIU, was in her dorm room during the shooting. Morrissey said she first found out about the shooting at about 3:20 p.m. through a phone call from her roommate after the university sent out an e-mail warning students about a gunman on campus. She said she immediately turned on the news.

"The news reports were very, very inaccurate because they kept changing so much," Morrissey said. She said it was frustrating not knowing what was really going on because the first reports said there were no casualties.

Morrissey said authorities arrived quickly and the campus was crawling with security, police and FBI agents. She said the campus was put on lockdown, and people were searched and had to show several forms of identification to enter the dorms until the shooter was confirmed dead a little after 4 p.m.

The gunman was identified as Steven Kazmierczak, a 27-year-old graduate student at the University of Illinois Urbana-Champaign. Kazmierczak had been enrolled as a graduate student at NIU last spring. A motive for his actions is not yet known, according to the AP.

Although she did not know her personally, Morrissey had a women's studies class with one of the victims, 20-year-old Catalina Garcia.

Morrissey said it is shocking to realize that such a tragedy occurred so shortly after the Virginia Tech massacre last April when 32 were killed. But she said she thought police officers did everything they could and the shooting could not have been prevented.

NIU received threats of a shooting last December through a message on a bathroom wall stating black students were going to be killed. Morrissey said the university responded by canceling classes for the day.

The threat does not seem connected to Thursday's shooting, according to the AP.

But despite last week's events, Morrissey said she does not feel any less safe at NIU.

"It's not the school. There's just a lot of crazy people out there," Morrissey said. "It could basically happen at any school."

Matt Gill, a junior at NIU, said he first heard about the shooting through phone calls from friends at about 3:10 p.m.

"At first I kind of brushed it off like 'Nah, this must be a joke,'" Gill said.

But he said it became real when everyone around him received similar phone calls and when he noticed entire streets blocked off by police.

Gill said the NIU atmosphere will never be the same.

"The overall mood of everyone was indescribable. Some people were crying, some were just quiet and others tried to carry on with their normal afternoon," Gill said. "It still hasn't sunk in that this kind of thing actually happened at my school."

But Gill said he felt the university handled the situation the best it could. He said the classroom in Cole Hall where the shooting took place is closed for the rest of the semester.

"Many people might not feel safe anymore, but based on the way our police, university and community responded, I feel as safe as ever," Gill said.

Burton, however, said she planned to attend the prayer vigils over the weekend but did not want to leave her apartment.

"I would rather just stay in my apartment and be safe," Burton said.

She said she left for the first time Sunday because her roommate took her to a prayer vigil. She said the campus is empty because classes are cancelled until Monday.

"It's going to be really weird to go back on campus," Burton said.

In addition to counseling, Burton said the university is offering activities that allow students to come together, such as international students who cannot go home to their families. She said there will be a memorial service Sunday before classes resume.