By Patricia Reaney

NEW YORK (Reuters) - Nearly four years after the shocking massacre at the Sandy Hook Elementary School, a new film, "Newtown," explores how a small Connecticut town has coped with the aftermath of the deadliest shooting of schoolchildren in U.S. history.

The film, which opens in New York on Friday, begins with a late-summer parade, a scene that highlights the innocence of what was in many ways a typical American town.

It then switches to a recording of the 911 call on the morning in December 2012 when 20 first graders and six educators were shot dead by a disturbed young man. "Newtown" shows how the event changed life in the town forever.

"It is that feeling of a joyful summer and then boom it's gone," said Kim A. Snyder, the director of the film, which made its debut earlier this year at the Sundance Film Festival.

Snyder, who spent three years on the project, found a strength and dignity in the people of Newtown as they attempted to come to grips with the unthinkable.

"It explores the process of grief and efforts at making change," the 55-year-old director explained.

"Newtown" depicts members of the community as victims whose pain has endured long after the television cameras and news crews left town.

Parents of three of the children who were killed speak about how the shootings have devastated them. A surviving teacher, a first-responder, a custodian at the school, a neighbor and others share their experiences as well.

"It was a way of bearing witness and giving them voice to whatever they were feeling," said Snyder.

She makes no mention of the gunman, who killed himself, and even though parents who lost children have pushed for stricter gun laws, "Newtown" is not a film that directly addresses the issue of gun law reform.

"This was not about him or that," Snyder said. "I felt this film had to stay with the point of view of the survivors and aftermath and what is left in the wake."

The film shifts back and forth in time to reflect the feeling, relayed by people in the community, of being lost in time. Snyder suspects that is one of the hallmarks of trauma.

Since the massacre, there have been 1,162 mass shootings in the United States, including 49 people killed and 53 injured in a gay nightclub in Florida earlier this year, according to non-profit Gun Violence Archive.

"We want people to come away from the film with the idea that this has reached a critical point in the country and we need do something about it," said Snyder.

"Newtown" will also be released in Los Angeles and be shown in a national broadcast in 300 theaters, as well as in community screenings.

(Editing by Frank McGurty, Bernard Orr)