Mayhem struck at an elementary school in the northeastern state of Connecticut after a gunman opened fire and killed 26 people - most of them young children.
The mass shooting took place Friday morning at Sandy Hook Elementary School in Newtown, Connecticut, a small town 130 kilometers northeast of New York City.
Connecticut State Police Lieutenant J. Paul Vance told reporters the fatalities included students and staff, and that the gunman involved also was dead. By mid-afternoon, a police spokesman told reporters the crime scene had been secured. He said the first emergency call came shortly after 9:30 a.m. Police descended on the scene and immediately entered the school. Eighteen of the children and six adults, including the shooter, were found dead in one section of the school in two separate rooms. Two other children died in area hospitals.
A boy is comforted outside Sandy Hook Elementary School after a shooting in Newtown, Connecticut, December 14, 2012.
A police officer keeps guard from a hill top over looking Sandy Hook Elementary School. At least 20 people, including children, were killed on Friday when a shooter opened fire.
Parents leave a staging area after being reunited with their children following a shooting at the Sandy Hook Elementary School.
This satellite image provided by Google shows the Sandy Hook Elementary School in Newtown, Connecticut.
A woman waits to hear about her sister, a teacher, following a shooting at the Sandy Hook Elementary School in Newtown, Connecticut.
The scene at Sandy Hook Elementary School in Newtown, Connecticut, December 14, 2012.
White House press secretary Jay Carney told reporters that President Barack Obama is receiving updates on the situation in Connecticut during the daily press briefing at the White House in Washington.
Family members embrace each other outside Sandy Hook Elementary School.
It is widely reported that the 20-year-old suspect's mother - a teacher at the school - was among the dead. Circumstances of her death remained unclear hours after the tragedy. The gunman's 24-year-old brother was undergoing police questioning late Friday.
An official from the governor's office says Governor Dannel Malloy was "horrified" by the tragedy and rushed to meet with the children's family members.
Photos and video images from the scene showed children being rushed out of the school, but it took several hours before the full scope of the tragedy to become known.
When it did, reports of heroism surfaced as well. In one widely reported instance, a teacher herded her entire first grade class into a bathroom, locked the door, and cowered alongside the children until help arrived.
Tearful Obama calls for action
President Barack Obama called authorities in Connecticut to express his sadness, and pledged to help with federal resources. The White House said Obama spoke with the FBI director about the case, and received frequent briefings.
A tearful president expressed ``overwhelming grief'' for the victims of the shooting rampage and called on Americans to set aside politics and ``take meaningful action'' to prevent more tragedies of this kind.
``Our hearts are broken today,'' Obama said, his voice breaking at times during a nationally televised appearance in the White House briefing room.