Samantha Mathis Speaks Out About the Night Boyfriend River Phoenix Died 25 Years Later

Samantha Mathis is opening up about the tragic night her boyfriend, actor River Phoenix, died in 1993 on Halloween at the age of 23.

The American Psycho actress was with Phoenix and his younger brother Joaquin Phoenix when the Running on Empty actor died of a drug overdose outside of the Viper Room in Los Angeles.

Mathis, 48, told The Guardian in a phone interview that she accompanied Phoenix to the Viper Room, a Los Angeles club then-owned by Johnny Depp.

The actress said she thought they were there to drop off his siblings “but when we arrived he said to me, ‘Oh, there are some people playing music tonight in the club who want me to play with them — that’s Okay, right?’”

Mathis admitted to the publication the idea didn’t sit right with her, saying, “I knew something was wrong that night, something I didn’t understand. I didn’t see anyone doing drugs but he was high in a way that made me feel uncomfortable — I was in way over my head.”

“Forty-five minutes later, he was dead,” Mathis said.

She recalled the actor’s focus was always on his family, which includes sisters Rain, Summer and Liberty Phoenix.

“River said to me in that last year: ‘I just have to make one more movie to put away enough money so my youngest sister can go to college,’” Mathis said. “I don’t know if that was true, but I remember him saying that.”

The two costarred together in 1993’s The Thing Called Love. They met before then when she was 19 “and he bummed a cigarette off me in an LA club,” she told The Guardian.

“This sounds incredibly cheesy but I knew I would be with him one day,” Mathis explained. “It just felt fated between us, and there was such chemistry.”

“I think we recognized something in each other,” she said. “We came from very different families, but perhaps there were some broken parts in each other we recognized. We found safe harbor.”

The Broken Arrow actress revealed she and Phoenix “just hung out with his siblings and got to be kids” during his last year of life.

“He was so good at hanging out,” she said.

On the night of Phoenix’s death, Mathis said she “knew he was high that night, but the heroin that killed him didn’t happen until he was in the Viper Room.”

“I have my suspicions about what was going on, but I didn’t see anything,” she told the publication, adding she had gone to the bathroom before seeing the actor pushed out of the club by a bouncer.

It was at that moment Mathis said she saw Phoenix collapse on the ground. It was Joaquin who called 911.

As for where Phoenix would be today, Mathis said he would be doing what he loved most.

“I think if River was still here, I think he’d be acting, directing, saving the environment, just living and hanging out,” she explained. “Oh gosh, wouldn’t that be nice?”

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Despite dying at such a young age, Phoenix made his mark on the world after starring in beloved films Stand By Me (1986), Running on Empty (1988) and My Own Private Idaho (1991). His final film, Dark Blood, was completed in 2012.

On the 20th anniversary of Phoenix’s death in 2013, a few friends and colleagues reminisced to PEOPLE about some of their favorite memories of the actor.

William Richert, director of 1988’s A Night in the Life of Jimmy Reardon, called Phoenix “a risk-taker, a guy who constantly astonished you.”