PARKLAND, Fla. — A former student opened fire at a Florida high school Wednesday, killing “numerous” people, sending students running out into the streets and SWAT team members swarming in before authorities took him into custody.

Frantic parents rushed to the scene and ambulances converged in front of the Marjory Stoneman Douglas High School. Live footage showed emergency workers appearing to treat possibly wounded people on the sidewalks.

The Broward County Sheriff’s Office tweeted Wednesday afternoon that “so far we have at least 14 victims.” The tweet added: “Victims have been and continue to be transported to Broward Health Medical Center and Broward Health North hospital.”

Broward County Schools Superintendent Robert Runcie said there were “numerous fatalities.”

“It is a horrific situation.” He added, “It is a horrible day for us.”

The male shooter, approximately 18, was a student at the school at one time, but was not at the time of the shooting, Broward County Sheriff Scott Israel said. He said the shooter was outside and inside the school at points during the attack, and taken into custody “without incident” about an hour after he left the school. Israel said police were waiting for the SWAT team to give them the all-clear so that they could go inside.

Noah Parness, a 17-year-old junior, said the fire alarm went off for the second time of the day about 2:30 p.m. He said he and the other students calmly went outside to their fire drill areas when he suddenly heard several pops.

“Everyone was kind of just standing there calm, and then we saw a bunch of teachers running down the stairway, and then everybody shifted and broke into a sprint,” Parness said. “I hopped a fence.”