Police are seen through a window (R) as they investigate a shooting at Marysville-Pilchuck High School in Marysville, Washington October 24, 2014. A student fatally shot one classmate and wounded four others when he opened fire in the cafeteria of the sch
Police are seen through a window (R) as they investigate a shooting at Marysville-Pilchuck High School in Marysville, Washington October 24, 2014. A student fatally shot one classmate and wounded four others when he opened fire in the cafeteria of the school on Friday, following a fight with fellow students, authorities said. The shooter took his own life as other students scrambled to safety in the latest outburst of deadly violence at an American school. REUTERS/Jason Redmond (UNITED STATES - Tags: CRIME LAW EDUCATION)
Police are seen through a window (R) as they investigate a shooting at Marysville-Pilchuck High School in Marysville, Washington October 24, 2014. A student fatally shot one classmate and wounded four others when he opened fire in the cafeteria of the school on Friday, following a fight with fellow students, authorities said. The shooter took his own life as other students scrambled to safety in the latest outburst of deadly violence at an American school. REUTERS/Jason Redmond (UNITED STATES - Tags: CRIME LAW EDUCATION)

Another gun violence incident hit a US campus on Thursday morning, wounding three students when the gunman open fired outside the Florida State University's Stozier Library.

Tallahassee police said cops ordered the gunman to drop his gun, but he fired at the officers, prompting them to shot back and kill him.

A graduate student who was inside the library recounted that after the gunshots, chaos ensued within seconds. The graduate student heard a male student with blood-covered pants shout that he was shot.

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The library is open 24 hours and was full with about 300 to 400 students studying for final exams. The university has about 40,000 students.

CNN reports that two of the injured students were rushed to Tallahassee Memorial Healthcare, with one is still in critical condition and the other stable. The third wounded student was treated and released at the shootout scene.

Right after the shootout, students were ordered to transfer to a classroom building beside the library where the shootout happened. By 4 am, authorities allowed the students to go home.

Florida State President John Thrasher, who is in New York and is making arrangement to return to Tallahassee, canceled classes for the entire day, but the campus remains open.

Michael DeLeo, Tallahassee chief of police, said the shootout was an isolated incident and it seems the gunman was acting alone, although the police are unsure if he is a student or an outsider.