Florida high school shooting plunges city into mourning

Students released from a lockdown embrace following following a shooting at Marjory Stoneman Douglas High School in Parkland, Fla., Wednesday, Feb. 14, 2018. (John McCall/South Florida Sun-Sentinel via AP)

PARKLAND, Fla. (AP) - Just before the shooting broke out, some students at Marjory Stoneman Douglas High School thought they were having another fire drill.

Such an exercise had forced them to leave their classrooms hours earlier. So when the alarm went off Wednesday afternoon shortly before they were to be dismissed, they once again filed out into the hallways.

That's when police say 19-year-old Nikolas Cruz, equipped with a gas mask, smoke grenades and multiple magazines of ammunition, opened fire with a semi-automatic weapon, killing 17 people and sending hundreds of students fleeing into the streets. It was the nation's deadliest school shooting since a gunman attacked an elementary school in Newtown, Connecticut, more than five years ago.

"Our district is in a tremendous state of grief and sorrow," said Robert Runcie, superintendent of the school district in Parkland, about an hour's drive north of Miami.