Marjory Stoneman Douglas High School’s students returned to class Wednesday morning, exactly two weeks after police say a former student, Nikolaus Cruz, opened fire with an AR-15 in a school building, killing 14 students and three school staff members.

The massacre is among the worst school shootings in history.

The event sparked a nationwide debate over school safety, and student survivors of the shooting launched a campaign to reform gun laws.

CNN reported that law-enforcement officers from many nearby towns and jurisdictions came to the school Wednesday morning to show their support, as lines of cars full of teachers and staff members arrived, and then school buses full of students rolled in.

In its wake, President Donald Trump moved to ban bump stocks — devices that allow guns to fire like automatic weapons — and has discussed expanding background checks for firearm purchases. He has also proposed training and arming teachers, a suggestion that has been largely rejected by educators.

Students continue to demand that lawmakers change gun laws, and several traveled to Washington Monday to speak to members of Congress. Students have pressured companies to end discount programs for NRA members.

Across the country, students who are now accustomed to regular lock-down drills to prepare for the possibility of a mass shooting, have staged walk-outs calling for more gun control.

For many students, the last two weeks have been punctuated by vigils, marches, funerals for classmates and teachers and trips to grief counseling. The last of the victims, Martin Duque, a soccer-loving freshman, was laid to rest Sunday, the same day students returned to campus for a brief orientation.

The students will mark their return by heading to their fourth period classes, the same classes they were in when the gunfire started two weeks ago.

The building where the violence unfolded — Building 12 — is now ringed by a chain-link fence; Broward County Public Schools is seeking state funds to tear it down so that students never have to return to it.

Classes will only run a half day for this week, and Principal Ty Thompson said in a tweet to students that they will focus on “emotional readiness and comfort not curriculum.”

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