NEWTOWN, CT (NEWS1130) – It’s a tragedy that shocked us all: the worst elementary school shooting in US history.

Adam Lanza walked into Sandy Hook Elementary, fully armed, at 9:35 the morning of December 14th, 2012. He drove there after fatally shooting his mother Nancy at their home in Newtown, Connecticut.

The kids were listening to their morning announcements over the PA when they heard shots in the background.

Wearing black military style gear, including a bulletproof vest and mask, Lanza fired more than 100 rounds in one area of the school. He killed 26 people, 20 of whom children aged six or seven. He then turned the gun on himself.

Many of the teachers were deemed heroes after that day; some took bullets while others told their students to grab a friend and head out to a nearby fire station. Some locked their kids in closets or bathrooms.

A nurse tells us she was told kids would be coming to the nearby hospital, but only three people ever showed up. Two of them ended up among the 20 children dead.

She adds a group of nurses decided to go to the school but there wasn’t much they could do. “All these parents were waiting for their children to come out. They thought that they were still alive. There’s 20 parents that were just told their children were dead.  It was awful.”

This tragedy also marked the first time most people had seen US President Barack Obama in tears. He says he addressed the nation that day as a parent.

“As a country we have been through this too many times, whether it’s an elementary school in Newtown or a shopping mall in Oregon or a temple in Wisconsin or a movie theatre in Aurora or a street corner in Chicago, these neighbourhoods are our neighbourhoods and these children are our children,” said Obama.

A few days following the shooting, Obama spoke at a vigil in Newtown.

“Here in Newtown, I come to offer the love and prayers of a nation. I am very mindful that mere words cannot match the depths of your sorrow, nor can they heal your wounded hearts. I can only hope it helps for you to know that you’re not alone in your grief; that our world too has been torn apart; that all across this land of ours, we have wept with you, we’ve pulled our children tight. And you must know that whatever measure of comfort we can provide, we will provide; whatever portion of sadness that we can share with you to ease this heavy load, we will gladly bear it. Newtown — you are not alone.”

The killings have brought forward a hefty debate about gun control and mental health care in the US.