There is a lot of misinformation being spread by Sandy Hook Hoaxer Conspiracy Theorists.  One of their primary contentions is that there are no photographs of children being evacuated. That is untrue.  Hundreds of students were photographed that day.  Many were photographed by Shannon Hicks during the immediate evacuation and many were photographed as they left the fire house.

Many people associate their view from the news broadcasts from after the shooting.   Most news photos are taken well after the evacuation. This is particularly true of the helicopter photos.
The evacuation of students began at about 10:00 a.m.    By the time the helicopters were on scene, the evacuation was over.