NEWTOWN, Conn. (CBSNewYork) — Tuesday marks nine years since a gunman armed with a semi-automatic rifle opened fire at Sandy Hook Elementary School in Newtown, Connecticut.

Twenty-six people were killed, including 20 children between the ages of six and seven years old, along with six adults.

READ MORE: Mayor Adams' Plan To Address Gun Violence Includes Return Of Plainclothes Police Unit


Gunman Adam Lanza, 20, killed himself as police converged on the school.

PHOTOS: Remembering Newtown Shooting Victims

The school was demolished 10 months after the shooting.

READ MORE: New York State Supreme Court Strikes Down Gov. Kathy Hochul's Mask Mandate

In a video, President Joe Biden said the nation owes the families more than our prayers, we owe them action.

“Every one of those families relives the news they got that day. Twenty precious first graders, six heroic educators, a lone gunman and an unconscionable act of violence. Everything changed that morning for you, and the nation was shocked,” he said.

The president said it was frustrating that Congress has not passed legislation to reduce gun violence.

Authorities say Lanza used his mother’s semi-automatic rifle in the shooting.

MORE NEWS: NYPD Officer Wilbert Mora Remains In Grave Condition At NYU Langone

Newtown public schools held classes remotely Tuesday, and Gov. Ned Lamont ordered flags across the state to be flown at half staff.

CBSNewYork Team