Updated

A former student dressed in black opened fire with a shotgun and two handguns from the stage of a Northern Illinois University lecture hall Thursday, killing five students and wounding more than a dozen others before taking his own life.

University President John Peters said there were a total of 22 casualties in what he described as a "rapid fire" attack that sent terrified students running for cover.

The gunman shot himself on the stage after a rampage that lasted no more than a few minutes.

The slain included four females and two males, including the killer, Peters said.

Four, including the gunman, died at the scene, and two died at the hospital, Peters said.

As of Thursday night, six patients in ctirical condition at Kishwaukee Community Hospital were transferred to other area hospitals, three were admitted and eight were discharged, according to the hospital's Web site.

Peters said the gunman was a Spring 2007 graduate student in sociology at NIU, but was not currently enrolled.

According to identification found on him, the gunman was enrolled in another, unidentified university.

Peters said authorities know of no motive. Police believe the gunman had a no criminal history.

The university president called the incident, "a terrible time of crisis."

Lauren Carr said she was sitting in the third row of the lecture hall when she saw the gunman walk through a door on the right-hand side of the stage, pointing a gun straight ahead.

"I try to be a good student and sit close to the front and this is what happens," said Carr, a 20-year-old sophomore. "I personally Army-crawled halfway up the aisle ... I said I could get up and run or I could die here."

She said a student in front of her was bleeding, "but he just kept running."

"I heard this girl scream, 'Run, he's reloading the gun."'

Witnesses said "someone dressed in black came out from behind a screen in front of the classroom and opened fire with a shotgun," Peters said.

Seventeen victims were brought to Kishwaukee Community Hospital in DeKalb, according to spokeswoman Theresa Komitas. One died, two were admitted and three were discharged; five were being evaluated and six others were transferred to other hospitals in critical condition.

One male died at OSF St. Anthony's in Rockford and three were taken to Good Samaritan in Downers Grove.

The shooting took place about 3 p.m. and was over in an instant.

"At this point I'm being told it was less than two minutes," Grady said. "This thing started and ended in a matter of seconds."

He said 911 calls started coming in at 3:06 p.m. and police were on scene 29 seconds later.

"Twenty-nine seconds was not fast enough," Grady said.

George Gaynor, a senior geography student, who also was in Cole Hall when the shooting happened, told the student newspaper the Northern Star the shooter was "a skinny white guy with a stocking cap on."

He described a terrifying scene.

"Some girl got hit in the eye, a guy got hit in the leg," Gaynor said outside just minutes after the shooting occurred. "It was like five minutes before class ended, too."

Student Edward Robinson told WLS-TV the gunman appeared to target students in one part of the lecture hall.

"It was almost like he knew who he wanted to shoot," Robinson said. "He knew who and where he wanted to be firing at."

Alan Edrinn, 21, a journalism major, arrived at the scene around 3:30 p.m. after hearing reports of the shooting.

"It was very chaotic," he said. "People were definitely in a panic. I saw some people running. Everyone was on their cell phone. I saw bodies on the sidewalk, it looked like two, people were attending to them," Edrinn said.

"Police were trying to get people back, there were people crying," he added.

The federal Bureau of Alcohol, Tobacco and Firearms sent 15 agents to the scene, according to Thomas Ahern, a spokesman. He said information about the weapons involved would be sent to the ATF's national database in Washington and given urgent priority.

The FBI also was assisting.

All classes were canceled Thursday night and the 25,000-student campus was closed on Friday. Students were urged to call their parents "as soon as possible" and were offered counseling at any residence hall, according to the school Web site.

The school was closed for one day during final exam week in December after campus police found threats, including racial slurs and references to shootings earlier in the year at Virginia Tech, scrawled on a bathroom wall in a dormitory. Police determined after an investigation that there was no imminent threat and the campus was reopened. Peters said he knew of no connection between that incident and Thursday's attack.

The shooting was the fourth at a U.S. school within a week.

On Feb. 8, a woman shot two fellow students to death before committing suicide at Louisiana Technical College in Baton Rouge. In Memphis, Tenn., a 17-year-old is accused of shooting and critically wounding a fellow student Monday during a high school gym class, and the 15-year-old victim of a shooting at an Oxnard, Calif., junior high school has been declared brain dead.

Click here for more on this story from MyFOXChicago.com.

The Associated Press contributed to this report.