NEWTOWN, CONN -- NEWTOWN - Twenty-seven people including 18 children were massacred in a horrific bloodbath at the Sandy Hook Elementary School this morning, sources told the Associated Press.
Few other details were immediately available, and other reports contradicted those numbers.
But local, state and federal authorities swooped down on the school about 9:40 a.m. after someone called 911 from inside the school and reported the shooting.
ABC News said state and federal sources told the network that dozens of victims had been shot, many of them fatally.
ABC said the shooter was an employee who had been fired earlier in the morning and returned with an assault weapon, shot a school employee and then shot himself.
The network quoted one parent who said that "hundreds of shots" were fired during the 9:40 a.m. incident.
Panicked parents rushed to the suburban school this morning after the unidentified gunman wounded a school employee, authorities and sources said. There were also reports that another gunman was involved, and Danbury police had surrounded a van in that city investigating the incident.
Several students were reportedly brought to Danbury Hospital's emergency room this morning, but the extent of their injuries was unclear.
While both ABC and CBS reported that multiple children had been shot, other sources said the pupils had been cut by flying glass caused by the shooting.
A 9-year-old student heard the gunshots this morning.
"I saw police with big guns," said Venesa Bajraliu. "It was a little scary."
She said she was in her classroom when she heard shots, about 20. The class was instructed to go into the teacher's office, she said.
Police came and took the students out, telling them to close their eyes.
Some reports identified the school employee as a teacher, and said she was wounded in the leg. Other reports from the scene indicated the school principal, Dawn Hochsprung, was shot and had been killed.
A hospital official confirmed that three people were transported from the scene to the hospital. No information on their conditions is immediately available.
Danbury Police Chief Al Baker said people were killed in the shooting, but offered no specifics. He brought in extra officers to Danbury Hospital to control the "chaos expected as parents and media arrive."
Children are being evacuated to the Sandy Hook firehouse and all schools in town are locked down.
A parent who picked up their child at the school reported that children were advised by a fireman to close their eyes and run past the office, where the shooting reportedly occurred during an administrators meeting.
Superintendent of Schools Janet Robinson is at the firehouse where parents are picking up their children. She has been trying to contact the school's principal.
Hocksprung became principal of Sandy Hook Elementary School July 1, 2010.
She was an administrator in Danbury public schools for six years, for five years as assistant principal of Danbury's Rogers Park Middle School and from 2003-2004, an assistant principal of Danbury High School.
Police are planning a press conference for early afternoon.
Andrea Rynn, spokeswoman for Western Connecticut Health Network, said Danbury Hospital's emergency department has convened its emergency team to be ready for the victims of this incident. She did not say how many victims are expected from the shooting.
Rynn said that "out of an abundance of caution'' the hospital put its emergency department on lockdown Friday. There is no direct threat to the department, she said.
Robinson said it is best if parents do not try to call the school at this time. The school district will release a message once further information is known.
Danbury parochial schools and Bethel schools are in lockdown as a precaution. Danbury schools are keeping close watch.
Baker said he brought an extra shift of officers for the schools. While indications are the Danbury schools are safe, he said it would be "prudent to take precautions."
"We are doing our due diligence to make sure our schools are safe," Baker said.
The White House said President Barack Obama was notified of the shooting.