At least 17 people were killed Wednesday in a high school massacre in Parkland, Florida, the Broward County Sheriff’s office said.

The shooting, which is among the 10 deadliest mass shootings in modern US history, revived debate over gun control while American politicians offered their condolences.

The school is closed for the rest of the week, Broward County Public Schools Superintendent Robert Runcie said. The district will offer grief counseling to students and their families.

“This has been a day where we’ve see the worst of humanity. Tomorrow is gonna bring out the best in humanity as we come together to move forward from this unspeakable tragedy,” he said.

The suspect, 19-year-old former student Nikolas Cruz, is in custody, Sheriff Scott Israel said.

During the election, the issue of gun rights became a major issue of disagreement between the two candidates. While Donald Trump promoted himself as a staunch defender of the Second Amendment, Clinton said she felt sensible regulations on who was able to buy weapons and the need for background checks.

The National Rifle Association spent more on the 2016 elections than it had ever done – a a minimum of $36m, according to the Centre for Responsive Politics.