This article originally appeared on Time. For more stories like this, visit time.com.

By TIME.COM/Lisa Marie Segarra and Katie Reilly
Feb 14, 2018 @ 7:30 pm
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Authorities said 17 people are dead after a former student opened fire at Marjory Stoneman Douglas High School in Parkland, Florida on Wednesday afternoon.

The suspected gunman — identified by the Broward County Sheriff’s Office as 19-year-old Nikolaus Cruz — has been taken into custody.

“This is a terrible day for Parkland, Broward County, the state of Florida and the United States. My very own triplets went to that school and graduated from Stoneman Douglas,” Broward Sheriff Scott Israel said at a press conference Wednesday. “It’s just catastrophic. There really are no words.”

This is at least the 18th school shooting of 2018. Here’s what we know so far:

17 people were killed in the school shooting

At least 17 people were killed in the shooting on Wednesday. Broward Sheriff Scott Israel said 12 people were killed inside the school. Three others were shot just outside the building and on a nearby street corner. Two victims died at nearby hospitals.

“Our worst fears are being realized. It looks like it’s a number of fatalities. Praying for all those students, families and school members affected at Marjory Stoneman Douglas High School,” Florida Sen. Bill Nelson said in a tweet.

Broward County Public Schools Superintendent Robert Runcie described the shooting as an “unspeakable tragedy” representing “the worst of humanity.”

The suspect has been identified as Nicolas Cruz

The sheriff’s office identified the suspected shooter as 19-year-old Nikolaus Cruz. The suspect — who authorities said was not a current student, but had previously attended the school — was taken into custody Wednesday after being found off campus. Israel said Cruz had been expelled from the school for disciplinary reasons.

The school was initially placed on lockdown, but started dismissing students as a SWAT team worked on clearing the school. Broadcast news footage showed students running from the school building with their hands up.

The FBI said it is responding to the situation and working with local law enforcement.

Leaders responded to the ‘horrible unfolding situation’

President Trump spoke with Florida Gov. Rick Scott, who said he will continue receiving updates on the investigation from law enforcement. In a tweet, Trump offered condolences to family members of the victims and said “no child, teacher or anyone else should ever feel unsafe in an American school.”

Florida Sen. Marco Rubio said he was monitoring the “horrible unfolding situation.” “Just spoke to Broward School Superintendent. Today is that terrible day you pray never comes,” he said in a tweet.

Meanwhile, Connecticut Sen. Chris Murphy — who has become a vocal advocate for gun control legislation in the wake of the Sandy Hook Elementary School shooting in his state — responded to the “horrific scene” while speaking on the Senate floor.

“This happens no where else other than the United States of America, this epidemic of mass slaughter, this scourge of school shooting after school shooting,” he said. “It only happens here — not because of coincidence, not because of bad luck, but as a consequence of our inaction. We are responsible for a level of mass atrocity that happens in this country with zero parallel anywhere else.”

Students and teachers described ‘the worst nightmare’

“This is the worst nightmare that you hope never happens to you,” Melissa Falkowski, a teacher at Marjory Stoneman Douglas, who escaped the shooting, told CNN on Wednesday.

Students at the high school have shared information about what happened, some while they were still hiding within the school.

Ryan Gott, a freshman at the school, told CNN that he heard one of his teachers had been shot and was telling students to run, but that he could not confirm anything independently of news reports.

Kayden Hanafi, a freshman at the school who ran to safety, also spoke to CNN and said she saw two people under a tarp at the school who she believed to be killed. One appeared to be an adult, she said, and another a female student, although she could not confirm the identity of either.