PARKLAND, FLORIDA — More than a dozen are dead after a gunman went on a violent rampage at a South Florida school.

The Washington Post reports that the incident began outside a Parkland, Florida high school, when a suspect armed with an AR-15, several magazines and a smoke grenade shot at least two people.

The gunman reportedly pulled a fire alarm to draw students out of their classrooms, before then open firing on them, according to USA Today.

Students hid in classrooms until SWAT teams arrived and ushered them out. Seventeen people have been confirmed dead so far.

The gunman left the scene and was apprehended by police an hour later, roughly a mile from the high school.

Authorities have identified the suspect as 19-year-old Nikolas Cruz, a former student who was expelled from the school.

Investigators looking into his social media accounts say they contained disturbing material.