The news channel cited a law enforcement official as saying the suspect is named Ryan Lanza and he is in his 20s. Dozens of law enforcement officials are outside the suspect's home, it said and his neighbors are "shaken".
The news channel cited a parent who was inside the school at the time of the attack as saying she heard what sounded like at least 100 rounds being fired. She said she saw two school employees who had died.
The shooting began about 9.30 a.m., the parent said. There was a "pop pop pop" in the hall outside the room. Three people went out of the room into the hall where the sounds had come from. "Only one person came back," she said.
The witness told CNN that she then called 911. She said she never saw the shooter but she later was escorted outside the room past two bodies lying in blood.