In the wake of the country’s deadliest school shooting since the 2012 rampage at Sandy Hook Elementary School in Newton, CT, President Donald Trump will address the nation.

The shooting at Marjory Stoneman Douglas High School in Parkland, Fla., which was carried out by an expelled former student, left 17 dead and at least 20 injured.

Trump offered “prayers and condolences” to the victims’ families , saying that, “No child, teacher or anyone else should ever feel unsafe in an American school.” He later tweeted about the alleged shooter, calling him “mentally disturbed” and urging the public to “report such instances to authorities, again and again!”

So many signs that the Florida shooter was mentally disturbed, even expelled from school for bad and erratic behavior. Neighbors and classmates knew he was a big problem. Must always report such instances to authorities, again and again!

— Donald J. Trump (@realDonaldTrump) February 15, 2018