Robbie Parker has a message for the family of the gunman who killed his 6-year-old daughter and 19 of her school mates.

"I can't imagine how hard this experience must be for you, and I want you to know that our family and our love and our support goes out to you as well," Parker said, as he remembered his oldest girl, Emilie Alice.

Emilie died Friday at the hands of a gunman who opened fire at her elementary school in Newtown, Connecticut, in the second deadliest school shooting in U.S. history.

The attack killed 20 children, between the ages of 6 and 7, and six faculty members at Sandy Hook Elementary School, before the suspect apparently committed suicide. Earlier, the man allegedly killed his mother, bringing to 27 the number of lives he took.

Fighting back tears with his voice cracking, Parker asked Saturday night that the tragedy "not turn into something that defines us, but something that inspires us to be better, to be more compassionate and more humble people."

Parker's comments came amid a public mourning in this southern New England town of 27,000, where residents have been trying to make sense of the shooting.

Many of the victims' parents asked for privacy as they grieve. But Parker, 30, stepped forward to talk about Emilie.

He moved his family from Utah to Connecticut eight months ago after accepting a job as a physician's assistant in the newborn unit at Danbury Hospital.

That's where he was when he got word of the shooting -- in a telephone call from his wife.

Parker, though, was unable to leave the hospital, which went into lockdown as a precaution over the school shooting.

"It went from ... 'I can't imagine this is happening. This has to be some sort of a mistake,'" Parker said.

"I didn't think it was that big of a deal at first. I thought with the first reports that were coming in it didn't sound like it was going to be as tragic as it was."

When the lockdown was lifted, Parker raced to a firehouse near the school where parents were gathering to wait for news of their children.

There, a photographer captured a photo of an agonized Parker and his sobbing wife, Alissa, as they left the firehouse, presumably after discovering their daughter was among the casualties.

On Saturday, Parker vacillated between present and past tense as he talked about his daughter, struggling to come to terms with Emilie's killing.

"My daugher Emilie would be one of the first ones to be standing up and giving her love and support to all of those victims, because that is the type of person she is," he said.

She was "an exceptional artist and she always carried around her markers and pencils so she never missed an opportunity to draw a picture or make a card for someone."

He recounted how his daughter slipped one of her cards in the casket at the funeral of her grandfather, who died in October in an accident.

She was the oldest of three girls, and helped one sister learn to read and helped the youngest to do crafts. "She was their best friend," he said.

Emilie's "laughter was infectious," he said. "This world is a better place because she has been in it."