Like most graduating seniors in the US, members of the Newtown High School's class of 2024 expect bittersweet feelings at their graduation ceremony.

But about 60 of the 330 kids graduating Wednesday, local time, will also be carrying the emotional burden that comes from having survived one of the deadliest school shootings in US history — and the knowledge many former classmates won't get to walk across the stage with them. 

Twenty of their fellow first graders and six educators were killed at Sandy Hook Elementary School in December 2012. 

The victims will be honoured during the graduating ceremony, but details have been kept under wraps.

'They'll be there with us'

Lilly Wasilnak, 17, was in a classroom down the hall from where her peers were killed in 2012. 

"I think we're all super excited for the day," she says. 

"But I think we can't forget … that there is a whole chunk of our class missing. 

"And so going into graduation, we all have very mixed emotions — trying to be excited for ourselves and this accomplishment that we've worked so hard for, but also those who aren't able to share it with us, who should have been able to."

Emma Ehrens, 17, was one of 11 children from Classroom 10 to survive the attack. 

She and other students managed to flee when the gunman paused to reload and another student, Jesse Lewis, yelled for everyone to run. 

Jesse didn't make it. Five kids and both teachers in the room were killed.

"I am definitely going to be feeling a lot of mixed emotions," Emma said.

"I'm super excited to be, like, done with high school and moving on to the next chapter of my life. But I'm also so … mournful, I guess, to have to be walking across that stage alone.

Grace Fischer, 18, was in a classroom down the hall from the killings with Ella Seaver and Lilly.

With only 11 days to go before Christmas, the school was in the holiday spirit and the children were looking forward to making gingerbread houses that day.

"As much as we've tried to have that normal, like, childhood and normal high school experience, it wasn't totally normal," she said. 

"But even though we are missing … such a big chunk of our class, like Lilly said, we are still graduating. … We want to be those regular teenagers who walk across the stage that day and feel that, like, celebratory feeling in ourselves, knowing that we've come this far."

Trauma responses remain for many 

Many of the survivors said they continue to live with the trauma of that day: Loud noises still cause them to jump out of their seats, and some always keep an eye on a room's exits. 

Many have spent years in therapy for post-traumatic stress, depression and anxiety.

The town provided an array of services to the families.

Officials shielded them as much as they could from the media and outsiders, and the students said leaving such a protective community will be both difficult and somewhat freeing.

Matt Holden, 17, who was in a classroom down the hall from the shooting, said the event is still "always kind of looming over" the students. 

"I think leaving and being able to make new memories and meet new people, even if we'll be more isolated away from people who have stories like us, we'll be more free to kind of write our own story," he said.