Children of 'Amazing' Parents Killed in Limo Crash Are the 'Cutest,' But the Loss Is 'Tough'

Adam and Abigail Jackson were among 20 people killed on Oct. 6, 2018 when the party limousine they were in crashed in the rural town of Schoharie in upstate New York. The couple left behind two children and several loved ones still struggling to come to terms with the loss a year later.

Justin Cushing, Adam’s longtime friend who served as his best man, says the last year has been “tough,” but that the Jackson’s children — Elle, 2, and Archer, 5 — are doing well in their grandparents’ care.

“Every time I see them, they’re the happiest little kids,” Cushing — who also lost his brother Patrick Cushing and cousin Erin McGowan in the crash — tells PEOPLE. “It’s nice to see them out running around. They’re the cutest little kids, they’re sweet.”

As for how Elle and Archer have dealt with the circumstances, “They’ve been doing as well as you could expect,” says Justin, who told PEOPLE last year that Abigail and Adam were “amazing” and “devoted” parents.

“I’m sure it’s tough,” he says of life one year later. “I know it’s tough on [their grandparents].”

For his part, Justin is still coping with loss of his best friend Adam, whom he’s known since their time playing baseball in grade school.

“You don’t have too many people that are with you through all of your phases of life as you get older,” Justin, 35, tells PEOPLE. “Those are the people you really cherish … those are the types of people that you really can’t replace. That makes it extra difficult when you lose someone like Adam.”

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The Jacksons were celebrating their friend Amy Steenburg’s 30th birthday when the limo they were traveling in failed to stop at a T-intersection. The limo flew into a nearby parking lot and crashed into an unoccupied SUV, killing the driver and all 17 passengers. Also killed were two pedestrians, who were struck by a parked SUV after it was slammed into by the limo.

Justin described Abigail and Adam as longtime sweethearts who cherished being parents to their two young children. Over the course of their 15-year friendship, Justin was able to see first-hand Adam and Abigail’s relationship evolve from a budding romance to a loving marriage.

“I went to college with Abby, his girlfriend at the time,” Justin recalled to PEOPLE last year, “and he knew even though they were apart, he had someone he could trust there for her.”

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A GoFundMe page set up in the wake of the death has raised more than $156,000. According to the campaign, donations raised from the page are given to the children’s grandmother Beth for expenses and schooling as the children grow up without their parents.

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Justin has grown closer with Adam and Abigail’s family since the accident, and a few of their relatives even attended Justin’s wedding last month.

“I had a picture of Adam and Abby in my pocket and I shared an extra I had with his mother,” says Justin, recalling the wedding. “We got to sit. We had some tears and hugged each other. We joked that if Adam was there, he’d be trying to pull some practical jokes. And it would be Abby stopping him.”