Heartwrenching: Masked gunman kills 27, including 18 children, at US primary school [UPDATE PHOTOS]

Michelle McLoughlin/REUTERSYoung children wait outside Sandy Hook Elementary School after a shooting in Newtown, Conn.

Twenty-seven people were killed, including 18 children, when a masked gunman unleashed a bloody Friday morning rampage through a Connecticut elementary school.
The mass murderer was a 20-year-old man who used a .223-caliber rifle. He was among the dead at the Sandy Hook Elementary School in Newtown, Conn. — a small suburban town of about 27,000 people.
The gunfire erupted around 9:40 a.m. inside the main office, sending terrified parents flocking to the school for word about their kids.
President Obama was briefed on the mass killing in Fairfield County, according to the White House.
Terrified children described hearing the gunshots as their teachers quickly hustled them to safety.
“I was in the gym and heard several loud booms … we all just huddled … and our teachers told us to go into the office where no one could find us. Then a police officer came in and told us to run outside,” one little girl told WVIT-TV.
GoogleSandy Hook Elementary School in Newton, Conn. is in Fairfield County in the southwest corner of the state.
Brenda Lebinski was among the anxious parents outside the school, looking for her 8-year-old daughter.
“I saw her and it was the happiest moment of my life,” she said.
Dad Stephen Delgiadice said his 8-year-old daughter, who escaped unharmed, reported hearing two big bangs before teachers told her to get in a corner.
“It’s alarming, especially in Newtown, Connecticut, which we always thought was the safest place in America,” he said.
Lines of children picked their way through shattered glass as they were led by teachers from the school. Video captured a long line of ambulances and law enforcement vehicles parked outside the school.
At least three people were treated at Danbury Hospital, including a teacher who was shot in the foot, police sources said. A witness spotted two wounded children — one had a bloody face, the other with a hand injury, WTNH-TV reported.
Two guns were found near the shooter, who died at the scene, according to law enforcement officials. Witnesses said the shooter was wearing a mask but his or her identity was still unknown.
A “platoon” of state troopers were combing the scene, said Lt. Paul Vance. of the state police. The FBI is also assisting.
The entire school district has been placed on lockdown “to ensure the safety of all students and staff,” Newton Public School District said is a statement.
A triage area has been set up outside the school and ambulances and stretchers set up, waiting for potential victims.
Gov. Dannel Malloy’s office said via Twitter: “State Police are coordinating w/ federal & local authorities in Newtown. Will provide add’l updates as they become available.”