President Donald Trump will make a national address at 11 a.m. Thursday, a White House spokeswoman said, about a massacre at a Florida high school on Wednesday in which a 19-year-old gunman killed 17 people in one of the country's deadliest school shootings.
Earlier on Thursday, Trump wrote in a Twitter post: "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!"
He also ordered flags lowered to half-staff because of the tragedy.