27 Dead; 20 Children in Elementary School Shooting

The nation is stunned by the shooting at an elementary school in Newtown, Connecticut that left 27 dead, 20 of them young children. INSIDE EDITION reports.

27 people are  dead—18 of them children, in one of the worst school shootings in American history.

It happened at Sandy Hook Elementary School in Newtown, Connecticut.

When news of the slaughter first broke, there was no indication of the awful extent of the unfolding tragedy. But it quickly became an event so shocking, even veteran reporters had difficulty reporting the news.

The school looked like a battle zone with heavily armed SWAT teams assembled outside.

One father told reporters, "My son was in the gym when it happened, so he heard the gunshots. I think it's going to be one of those things where they're trying to understand what happened, and when we tell them ultimately what happened, the details, I think it's going to make it much worse."

Terrified children, hands on each others shoulders, were evacuated to safety. The expression on one little girl's face showed the horror.

Distraught parents waited outside the school, deperate for news.

Grief and fear was etched in the face of one mom. Another image showed too children cowering in terror. One little boy was taken out wearing a policeman's jacket to keep warm.

It was the second mass shooting in America in a week. On Tuesday,  a gunman opened fire on shoppers at a mall in Portland, Oregon, before turning the gun on himself.

Experts say the shooting underlines the need for realistic drills at schools across the USA.

Safety expert Steve Kardian told INSIDE EDITION, "It hits us even worse because these children are so young. They are so helpless. They cannot defend themselves. They cannot comprehend what is going on. They are very, very soft targets."

Some high school students in New Jersey went through a simulated attack by armed teens who open fire on the student body.

One training video shows what some experts recommend during an attack in school.

INSIDE EDITION's Diane McInerney asked Kardian, "What if that gunman actually enters the classroom? What do you do?"

"If the gunman enters the classroom and you believe you're about to be shot, you need to go for the gun. Neutralize his attack and yell for the kids to get out of there," said Kardian.

But many of the victims in today's elementary school massacre were kindergartners, too young to defend themsevles against a madman.