The Goodfellas star died in his sleep in the Dominican Republic, PEOPLE confirmed Thursday. He was engaged to Nittolo and was also dad to daughter Karsen, 23, with ex-wife Michelle Grace.
A source tells PEOPLE no foul play is suspected in his death and that Nittolo was with him when he passed.
Nittolo released a statement on Instagram Saturday, paying tribute to her late fiancé alongside a series of shots of the pair from over the years.
"My life these past couple of years have been nothing but truly magical. Ray and I share a deep love that I will cherish in my heart forever," she wrote. "We laughed daily and we were inseparable. The chemistry was wild in the best way."
Then writing that Liotta "was everything in the world to me," Nittolo continued, "We couldn't get enough of each other. The kind of real love that one dreams of."
She concluded: "He was the most beautiful person inside and out that I've ever known…and even that is an understatement."
Liotta revealed his engagement to Nittolo, a mom of four, on Christmas in 2020, writing on Instagram, "Christmas wishes do come true. I asked the love of my life to marry me, and thank God she said yes!!!"
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This past November, Liotta opened up to PEOPLE about growing closer with Nittolo during isolation amid the COVID-19 pandemic.
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"Luckily, I had met somebody, and it brought us really, really close, to the point now where I'm engaged," he said at the time. "So I like to think that was the reason. I've heard that there's a lot of people whose relationship didn't work out because they were with each other so much. But she's just great."
Nittolo's most recent Instagram upload before Liotta's death was from Jan. 25 — a smiley beach photo of herself with Liotta from a trip to the U.S. Virgin Islands, plus a second snapshot of the two sharing a kiss. She captioned it with a heart and palm tree emoji.