A former student who had been expelled for disciplinary problems was arrested in a shooting Wednesday at a Florida high school that left 17 people dead.

Broward County Sheriff Scott Israel, calling it a “horrific day,” identified the alleged gunman as Nicolas Cruz and said police had arrested him off school grounds without a struggle.

Cruz had multiple magazines and one rifle, the sheriff said.

Israel said 12 of the victims died inside Marjory Stoneman Douglas High School in Parkland, Florida, about 72 kilometers (45 miles) north of Miami. Three others were killed outside the school, and two died of their wounds at a hospital. At least 14 others were wounded.

He said the victims included students and adults, but he said he did not know whether any of the adults were teachers.

The FBI was on the scene and was leading the investigation, working with police.

Television pictures just after the shooting showed students streaming out of the school, many holding their hands high in the air to show they were unarmed.[xyz-ihs snippet=”adsense-body-ad”]Students told television networks that everything had seemed normal inside the school prior to the sounding of a fire alarm. They said they heard gunshots while they were leaving the building, and a number of students ran back inside for cover. Others fled to a nearby department store.

Video taken inside a classroom showed students crouched under desks. Some could be heard saying they saw bullet holes in a computer screen.

Others hid in closets, using their cellphones to text emergency messages to their parents.

President Donald Trump offered Florida authorities all the federal help they needed and tweeted his “prayers and condolences” to the victims and their families.

“No child, teacher or anyone else should ever feel unsafe in an American school,” he tweeted.

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