Story highlights Campus police killed the gunman after he refused to put down his weapon

The shooting occurred at Strozier library

"The library was packed," says Mary Coburn, the vice president of student affairs

FSU canceled all classes and exams for Thursday

(CNN) Florida State University students huddled together in the aisles of a packed campus library early Thursday after a gunman opened fire, injuring three.

Two of the shooting victims were taken to Tallahassee Memorial Healthcare. One was in critical condition; the other was stable, the hospital said.

The third victim was treated and released at the scene.

All three are students.

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Campus officers later shot the gunman to death after they asked him to drop his handgun, and he opened fire at them, authorities said.

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