CNN — 

The campus of Florida State University was bustling as the noon hour approached Thursday, with students walking between classes, anticipating their final exams and graduation day just a couple of weeks away.

Then, the tranquility was shattered by the sound of gunfire.

Students fled for their lives, leaving shoes and backpacks scattered on the lawn. Some found shelter in classrooms, hiding beneath desks, as police swarmed to the scene of what the Gun Violence Archive said is Florida’s sixth mass shooting of the year.

Two men, who were not students, were killed and five others were wounded in the shooting. Officers shot the suspected gunman, identified by authorities as FSU student Phoenix Ikner, 20, who is now hospitalized.

The first shot was fired by Ikner between 11:56 a.m. and 11:57 a.m., according to Tallahassee Police, as Ikner walked in and out of buildings and green spaces near the student union firing a handgun. Within four minutes, the suspect was shot by responding officers and taken into custody, after police received multiple 911 calls and the school went on lockdown.

Video and photos from the Florida State University campus in Tallahassee captured how the campus reacted as the mass shooting unfolded.

Students sprinted away in all directions from the student union area after hearing gunshots. Videos obtained by CNN show students frantically escaping the area as the reverberating sound of gunshots was replaced by the echoing sirens of officers responding to the scene.

Video: FSU students shelter in place during school shooting

00:05 – Source: CNN

FSU shooting witness records gunshots ringing out on campus

00:12 – Source: CNN

Social media videos obtained by CNN show multiple angles of students running across campus to escape the shooting.

As the lockdown began, students and staff received emergency alerts on their phones, urging them to shelter in place. Students in classrooms heard emergency messages from an intercom as many hid under their desks and texted their loved ones.

Student shelters in classroom during lockdown as FSU warning plays in background

00:55 – Source: CNN

Some students barricaded the entrance to their classroom with a pile of chairs and desks during the shooting.

Students can be seen texting their loved ones and friends as they hid beneath desks in a dimly lit classroom.

Officers knocked on doors and evacuated students from classrooms to safe spaces over the next few hours. Students followed officers holding their hands up in a sense of disbelief a shooting had just occurred on campus.

Florida State University’s emergency message system urged students to shelter in place at 12:02 p.m., when the first alert was posted, until 3:18 p.m. when the school announced law enforcement officers had neutralized the threat.

In the distance, first responders wheeled stretchers along a street lined with police vehicles, as sirens echoed in the distance.

Officers evacuated students from classrooms, as students walked away in shock. One student, Holden Mamula, 20, was in his calculus class when he heard sirens in the distance and an active shooter alert. Once he was escorted out of the building, “I saw this police officer with an assault rifle, and I was like, ‘Oh my gosh, this is real,’” he said.

Officers cleaned up blood along the sidewalk behind yellow tape barring off a part of the crime scene near the student union in the early evening hours after the shooting.

CNN returned to the scene Friday morning and saw a table of untouched T-shirts, a backpack and a half-full soda bottle, frozen in time.

CNN’s Alaa Elassar contributed to this report