The terrifying videos from Marjory Stoneman Douglas High School place viewers right inside the bloodied classrooms and hallways of the school. We can hear the gunshots and the cries for help. We can see the bodies on the floor.

That's what is different about this episode of mass murder.

So much of the coverage from Parkland, Florida is numbingly similar to Columbine, Virginia Tech, and numerous other shooting sites. We're all too accustomed to seeing videos of students fleeing campus; interviews with eyewitnesses; reunions with parents.

But we're not used to being transported to the crime scene through the cell phone cameras of the victims. This is new and blood-curdling.

In one video clip, we see that some students had to walk by several lifeless bodies while being evacuated from the building.

In another clip, we hear gunshots and screams, then more gunshots, more screams.

Perhaps these up-close views -- through the eyes of the victims -- will force Americans to see these shootings in a new way. Perhaps.

CNN and other television networks showed a video that a student took from the floor of his classroom, capturing the sound of the gunfire. Anchors warned viewers in advance that the content was disturbing.

"This is what kids and their teachers went through. This is how it looked, how it sounded and how it felt for them," Savannah Guthrie said on NBC's "Today" show Thursday morning.

After the clip aired on "Today," co-host Hoda Kotb said, "there's something about seeing that video that puts you exactly where those kids were."

There were similar videos from the concert in Las Vegas, Nevada where 58 people were murdered last October. Concertgoers who were filming the show captured the gunfire and the chaos that followed.

But this is still a relatively new development in the way that people collectively process a mass shooting.

Students at the high school posted alerts on Twitter and videos on Snapchat while the attack was still underway.

"There's a real school shooting going on right now i'm not even playing i just heard 10 gunshots there's police everything i'm shaking," @Luvanth wrote at 2:42 p.m. Wednesday. That tweet triggered a Dataminr alert in many newsrooms, spurring news coverage of the attack.

"I'm at a school shooting right now," @Thecaptainaidan wrote at 2:59. This user also posted photos from the lockdown, which have now been seen all around the world.

In a photo of a bullet-strewn classroom posted to Snapchat, a user pointed out, "there's bullet holes in the f---ing computer."

Several cell phone videos began to circulate right away.

"My little brother just sent me this video of the swat team evacuating his classroom at stoneman douglas," a user named Melody posted on Twitter.

Students could be seen raising their hands in the air while the officers swarmed the room. Some of the students were shaking with fear.

In another video, emergency workers could be seen carrying one apparently injured student out of a classroom.

During the lockdown, students also texted loved ones. In some cases, they begged siblings and parents to call 911 for help.

A user named Kaitlin posted what she said were texts from her sister inside the school.

"i am so scared kaitlin."

"tell them i love them so much."

"im so scared."

"tell them i love them so so much."

Kaitlin said her sister survived. Seventeen students and teachers died in the attack.