Eitan Kilchevsky, 62, a neonatologist at Danbury Hospital, helped take care of Caroline Previdi when she was born and followed her progress through her aunt.
On Sunday he recalled what he tells all families when they first take home their child.
"We tell the parents, 'The kid is OK, the kid is fine, we don't see any problem, go home, raise her and be happy,' " he said. "You tell them, 'Invite me to their wedding.' "
Instead, Kilchevsky will attend Caroline's funeral, he said. She was one of 20 children gunned down at Sandy Hook Elementary School.
"You send a baby home with hopes of a long life of happiness and in a loving family," he said. "Now what do you tell them? There was so much ahead of her, so much potential. You see her and she is gorgeous and developing and growing. It's like you go from the height of happiness to the bottom of darkness."