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Students and passersby alike were in a state of panic when gunfire erupted at a South Florida high school on Wednesday — and the internet was able to watch in almost real time.

Social media users shared heart-rending scenes, including one recorded from within his classroom that shows several students sitting or lying down on the floor in between desks.

A caption on the video says the school is “getting shot up.” Loud bangs are heard, eliciting screams and curses in the background, then at the end of the video, a still image of a computer screen with bullet holes is shown.

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Related: 17 killed in shooting at high school in Parkland, Florida, authorities say

Another video that comes from the Snap Map feature, which geotags video location, shows a slew of police cars stuck in traffic near the school in Parkland, Florida. Police sirens screech loudly in the background. When the next Snapchat story appears, a television above a chimney shows a local news channel premiering from an elevated view the chaos by the school.

My little brother just sent me this video of the swat team evacuating his classroom at stoneman douglas. So scary but glad he's safe. @nbc6 @CBSMiami @NBCNews @wsvn @CBSNews pic.twitter.com/XNTtra221q — Melody (@Melody_Ball) February 14, 2018

Another video shot from within a car going by the scene has a caption that reads, “I’m super sad I just saw mad kids hiding in the busheses [sic].” In the footage, armed police officers crouch at raised highway ledge, peering down on the scene from below.

One video filmed by a student shows other terrified students crouching under and behind desks. The girl in the middle clutches her hand over her mouth as gun shots blare near Douglas High.

The shooting, which began at 2:30 p.m. on Wednesday, resulted in the deaths of 17 people, both inside and outside of the Marjory Stoneman Douglas High School, officials said.

Broward County police said that suspect Nikolas Cruz, 19, is a former Douglas High student who had been expelled. He was taken into custody about an hour after the shooting.