Mimi O'Donnell opens up on partner Philip Seymour Hoffman's death

Mimi O'Donnell, partner of Philip Seymour Hoffman for 15 years and mother of his three children, opened up about her relationship with the late actor and his struggles with addiction. O'Donnell, who is a director and producer, spoke about Hoffman in a piece for Vogue.

She recalled him as a "sweet and gentle and loving man." O'Donnell said she fell in love with him in the fall of 2001, and got pregnant the following year. O'Donnell said that years later, when she and Hoffman were living together with three children in the West Village of New York City, she "couldn't have imagined a better life." But O'Donnell, who knew Hoffman was a recovering addict, said, "At the time I didn't fully understand that addiction is always lurking just below the surface, looking for a moment of weakness to come roaring back to life." And she added, "Something was brewing." 

O'Donnell said that Hoffman wanted to try drinking again, though he had been sober for more than 20 years. She said things seemed under control until she realized he was also abusing drugs. 

"He started having a drink or two without it seeming a big deal, but the moment drugs came into play, I confronted Phil, who admitted that he'd gotten ahold of some prescription opioids," she said. "He told me that it was just this one time, and that it wouldn't happen again. It scared him enough that, for a while, he kept his word." O'Donnell said that starring in Mike Nichols's production of "Death of a Salesman" kept Hoffman extremely busy, but afterward he started using prescription drugs again. 

O'Donnell said soon things took a turn for the worse: "As soon as Phil started using heroin again, I sensed it, terrified," she said. "I told him, 'You're going to die. That's what happens with heroin.' Every day was filled with worry. Every night, when he went out, I wondered: Will I see him again?"

O'Donnell said that after Hoffman acted strangely around their children and spent two stints in rehab, she told him, "I can't monitor you all the time. I love you, I'm here for you, and I'll always be here for you. But I can't save you." She said she and Hoffman made plans to set up rehab for him when he returned from shooting "The Hunger Games" in 2014, but he died three days after he came home.

She said when she heard the news, she was hit with "brutal force."

"I wasn't prepared," she said. "There was no sense of peace or relief, just ferocious pain and overwhelming loss." O'Donnell said that only her kids kept her going.

"It's been almost four years since Phil died, and the kids and I are still in a place where that fact is there every day. We talk about him constantly, only now we can talk about him without instantly crying."

In February 2014, Hoffman was found dead in his Greenwich Village apartment after a 911 emergency call from a friend of his, according to law enforcement sources. Hoffman was supposed to be somewhere this morning and when he did not show up the associate went to the apartment where Hoffman was discovered.

Law enforcement sources also say he was found with a syringe in his arm and there were glassine envelopes in the apartment believed to have contained heroin, CBS News senior investigative producer Pat Milton reported.