Students return to Florida school where 17 were killed in a mass shooting

Thousands of students joined their parents in walking past the three-story building at Marjory Stoneman Douglas High School where the Feb. 14 massacre took place.

Mourners pay tribute at a memorial for the victims of the shooting at Marjory Stoneman Douglas High School on Sunday, Feb. 25, 2018, in Parkland, Fla. (David Santiago/Miami Herald via AP) 

Mourners pay tribute at a memorial for the victims of the shooting at Marjory Stoneman Douglas High School on Sunday, Feb. 25, 2018, in Parkland, Fla. (David Santiago/Miami Herald via AP)

Mourners pay tribute at a memorial for the victims of the shooting at Marjory Stoneman Douglas High School on Sunday, Feb. 25, 2018, in Parkland, Fla. (David Santiago/Miami Herald via AP)

Parents and students arrive at Marjory Stoneman Douglas High School for an open house on Sunday, Feb. 25, 2018, in Parkland, Fla., as parents and students returned to the school for the first time since over a dozen were killed on Feb. 14. (David Santiago/Miami Herald via AP)

Mourners pay tribute at a memorial for the victims of the shooting at Marjory Stoneman Douglas High School on Sunday, Feb. 25, 2018, in Parkland, Fla. (David Santiago/Miami Herald via AP)

Seventeen people dressed as angels stand Sunday, Feb. 25, 2018, at the memorial outside Marjory Stoneman Douglas High School in Parkland, Fla., for those killed in a shooting on Feb. 14.

Parents and students arrive at Marjory Stoneman Douglas High School for an open house on Sunday, Feb. 25, 2018, in Parkland, Fla., as parents and students returned to the school for the first time since over a dozen were killed on Feb. 14. (David Santiago/Miami Herald via AP)

Parents and students walk into Marjory Stoneman Douglas High School on Sunday, Feb. 25, 2018, for an open house as parents and students returned to the school for the first time since seventeen victims were killed in a mass shooting at the school in Parkland, Fla. on Feb. 14. (David Santiago/Miami Herald via AP)

Pulse survivor India Godman, left, hugs Wendy Garrity at Marjory Stoneman Douglas High School in Parkland, Fla., Sunday, Feb. 25, 2018, for an open house as parents and students returned to the school for the first time since a shooting took place at the high school on Feb. 14. (David Santiago/Miami Herald via AP)

A man signs a banner as people pay tribute at a memorial for the victims of the shooting at Marjory Stoneman Douglas High School on Sunday, Feb. 25, 2018, in Parkland, Fla. (Associated Press)