Parents wait for news after a shooting at Marjory Stoneman Douglas High School in Parkland, Florida, on Wednesday, February 14. At least 17 people were killed at the school, Broward County Sheriff Scott Israel said. The suspect, 19-year-old former student Nikolas Cruz, is in custody, the sheriff said. The sheriff said Cruz had been expelled for unspecified disciplinary reasons. Joel Auerbach/AP

Police officers ride in the back of a pickup truck as they tend to a victim. John McCall/South Florida Sun-Sentinel/AP

People are brought out of the Marjory Stoneman Douglas High School after the shooting. Joe Raedle/Getty Images

Police officers surveil the exterior of the school while the shooting was active. WPLG

Students and faculty are evacuated from the school. Joe Raedle/Getty Images

A father and daughter embrace after a mass shooting at the Marjory Stoneman Douglas High School. SAUL MARTINEZ/The New York Times/Redux

Family members wait for word from students beneath an underpass just south of the campus of Marjory Stoneman Douglas High School. Sun Sentinel/TNS/Getty Images

Lavinia Zapata embraces her son, Jorge, after he was evacuated from the school. SAUL MARTINEZ/The New York Times/Redux

The suspect, 19-year-old former student Nikolas Cruz, is taken into custody by authorities. Cruz was apprehended off of the campus. WSVN

Security instructs parents following the shooting. Parents were told they would be reunited with their children at a local Marriott Hotel. MICHELE EVE SANDBERG/AFP/Getty Images

Students released from lockdown console each other. While some students were evacuated, many remained in the school until authorities could come to their aid. John McCall/South Florida Sun-Sentinel/AP

Family members embrace after shooting. Wilfredo Lee/AP