At least 28 people are dead, including 18 children, after a gunman opened fire in an elementary school in Newtown, Connecticut.
Frantic parents rushed back to Sandy Hook Elementary School, desperate for any information about their kids inside.
"We just ran like every other parent and found we couldn't get to the school," said one father.
"A friend of mine said a masked man came in and just started shooting," added woman outside the school.
Survivors said teachers scrambled to protect their students.
"We were doing morning meeting, we heard shots and everybody went on the ground. Ms. Martin closed the door and we went to the corner," said one student.
Police and SWAT teams surrounded the school and stormed outlying buildings.
The shooter, now identified as 20-year-old Adam Lanza, died inside the school.
It is believed Lanza drove there, where he killed his mother, a teacher, and her students.
Another body was found at a separate scene in Newtown that investigators say was linked to the crime.
The magnitude of the loss of life involving so many children has shaken this community and the nation.
"I know there is not a parent in America that doesn't feel the same overwhelming grief that I do," President Obama said after learning of the shooting. "The majority who died today were children beautiful little kids between the ages of five and ten years old."
Investigators are still working to confirm the identity of the gunman, and say he may have been carrying an ID card belonging to someone else.