Law enforcement vehicles arrive at a hotel where parents were instructed to pick up their children in Coral Springs, Fla., Wednesday, Feb. 14, 2018. (AP Photo/Wilfredo Lee)
Family members pick up students of Marjory Stoneman Douglas High School in Parkland, Fla., at a nearby hotel, Wednesday, Feb. 14, 2018. (AP Photo/Wilfredo Lee)
A woman consoles another as parents wait for news regarding a shooting at Marjory Stoneman Douglas High School in Parkland, Fla., Wednesday, Feb. 14, 2018. (AP Photo/Joel Auerbach)
Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect (AP Photo/Joe Skipper)
Family member embrace following a shooting at Marjory Stoneman Douglas High School, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
Students wait to be picked up after a shooting at Marjory Stoneman Douglas High School in Parkland, Fla., Wednesday, Feb. 14, 2018. (AP Photo/Wilfredo Lee)
Police and rescue vehicles are shown outside Broward Health North hospital, Wednesday, Feb. 14, 2018, in Deerfield Beach, Fla. (AP Photo/Joe Skipper)
A law enforcement officer tells anxious family members to move back, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
Family members embrace after a student walked out from Marjory Stoneman Douglas High School, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
Anxious family members watch a rescue vehicle pass by, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
Parents wait for news after a reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Fla., on Wednesday, Feb. 14, 2018. (AP Photo/Joel Auerbach)
A law enforcement officer talks with students, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
Anxious family members wait for news of students as two people embrace, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
A student shows a law enforcement officer a photo or video from his phone, Wednesday, Feb. 14, 2018, in Parkland, Fla. (AP Photo/Wilfredo Lee)
Photos from the scene show law enforcement response to a shooting at a Florida high school. (grumpyhaus/Twitter)
Students shelter in place during a shooting at a Florida high school. (TheCaptainAidan/Twitter)
Students shelter in place during a shooting at a Florida high school. (TheCaptainAidan/Twitter)
Photos from the scene show law enforcement response to a shooting at a Florida high school. (grumpyhaus/Twitter)
Photos from the scene show law enforcement response to a shooting at a Florida high school. (grumpyhaus/Twitter)
Photos from the scene show law enforcement response to a shooting at a Florida high school. (grumpyhaus/Twitter)
Authorities are responding to reports of shots fired at a Florida high school. (WSVN via CNN)
Authorities are responding to reports of shots fired at a Florida high school. (WSVN via CNN)
Authorities are responding to reports of shots fired at a Florida high school. (WSVN via CNN)
Authorities are responding to reports of shots fired at a Florida high school. (WSVN via CNN)
Photos show a police response to reports of shots fired at a Florida high school. (grumpyhaus/Twitter)
Photos show a police response to reports of shots fired at a Florida high school. (grumpyhaus/Twitter)
PARKLAND, Fla. -- A shooter 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 the shooter into custody.