When 46-year-old Philip Seymour Hoffman was found dead in his New York City apartment over the weekend, the news shocked the world and devastated Hollywood insiders, who considered him one of the... See More
When 46-year-old Philip Seymour Hoffman was found dead in his New York City apartment over the weekend, the news shocked the world and devastated Hollywood insiders, who considered him one of the finest actors of his generation. With only a week of filming left to go in the latest "Hunger games" movie. But his death also exposed a dangerous personal struggle. Dozens of bags of heroin found in his home. For more on those final hours, here's ABC's David Wright. Reporter: A tragic ending because of a secret struggle behind closed doors. An all too familiar Hollywood story. Philip Seymour Hoffman dead at age 46 of an apparent drug overdose. Last seen out with friends Saturday night, writer David Katz went looking for him Sunday morning after he failed to pick up his three kids. At 11:15 A.M. Katz found him in the bathroom of his greenwich village apartment, a needle stuck in his arm, a baggie of heroin nearby, one of 70 such bags authorities now say they found inside that apartment. Philip Seymour Hoffman didn't live or die like the typical troubled star. He was neither an aging diva like Michael Jackson or Whitney Houston, struggling desperately to rally for one big comeback, nor was he an early flame-out like Corey monteith or river Phoenix or heath ledger, shooting comets who did not live long enough to fulfill their early potential. T Oscar goes to -- Philip Seymour Hoffman in "Capote." Reporter: No, Hoffman won the best actor statue. And in his acceptance speech he seemed so humble, so grounded. My mom's name is Marilyn o'connor, and she's here tonight. And I'd like if you see her tonight to congratulate her because she brought up four kids alone. Reporter: A gifted actor. Some say the most gifted in his generation. He was a person with such scope and breadth that he could play anything. He could make you laugh. He could make you cry. He could terrorize you. He could thrill you. He could make you fall in love with him. Reporter: Hoffman's characters on stage and on screen often struggled to keep it together. From the high-strung medical student opposite robin Williams in "Patch Adams" -- This isn't play time! This is serious business! Reporter: To the sycophantic butler in "The big lebowski." That is the key to the city of Pasadena which Mr. Lebowski received two years ago in recognition of his various civic -- oh. That's the Los Angeles chamber of commerce business achiever award. Reporter: He often played characters wound so tight they seemed ready to burst. And sometimes they did burst. Can I kiss you? Scottie, I -- Please? Can I kiss you on the mouth? No! Reporter: In "Boogie nights" he was the stage hand nursing a secret crush on a male porn star. I'm a Idiot. Reporter: In "Charlie Wilson's war" the aging overweight cia agent railing against his button-down ivy league bosses. My loyalty? For 24 years people have been trying to kill me. People that know how. Now, do you think that's because my dad was a great soda pop maker or because I'm an American spy? Go Yourself, you Child. Reporter: That performance earned Hoffman one of his four Oscar nominations. How was I? Reporter: His talent widely celebrated. He was an actor's actor, like Meryl Streep, who starred opposite him in "Doubt." You've got it in your head that I corrupted this child after giving him wine, and nothing I say will change that. Reporter: Both of them got Oscar nominations for "Doubt." Whoo! Reporter: Hoffman also nominated for his role as a cult leader in "The master." I am a writer, a doctor, a nuclear physicist, a theoretical philosopher. But above all, I am a man. Reporter: But he won for "Capote." There's one singular reason I keep coming here. Truman. November 14th, 1959. Three years ago. Reporter: Hoffman was at sundance just a few weeks ago, looking slouchy. But that was his style. Not primped or groomed like your typical Hollywood star. But as "The New York times" put, it always rumpled and sleepy-looking, like an out ofwork actor. But out of work Hoffman never has been. At sundance he was promoting the upcoming John LE Carre movie, "A most wanted man." Your choice is between us and nobody. Reporter: The latest of many Hoffman characters who seem to be battling their inner demons. In Hoffman's own case addiction was part of the mix. As he told "60 minutes," his substance abuse problems predated his acting career. I got sober when I was 22 years old. Yeah. So this was drugs or alcohol or both? Yes. All that stuff. Yeah. Let me get my hands up. Yeah. Yeah. I liked it all. Yeah. Reporter: But he insisted he had it under control. Then in 2012 he checked into rehab for ten days. Not long enough says the director of one prominent malibu program. Anytime I have somebody with a ten-day, I know it's going to be a really bad outcome. These ten-day programs, they don't detox you in a way that will keep you sober. Because you're just using it as a gimmick. And whenever you use any type of detox as a gimmick, that means you're really still wanting to get high. Reporter: Hoffman's intensity was obvious long before he ever started acting. To his high school English teacher back in Rochester, new York. I've never had a student make me feel so naked as he did because his intelligence when it came to the human condition was off the charts. Reporter: Never let it be said he just phoned it in. He did some of his best work on the phone. As the hard-nosed rock critic in "Almost famous." The only true currency in this bankrupt world is what you share with someone else when you're uncool. Reporter: Or the seedy mattress statement in "Punch drunk love." Shut up! Shut up! Shut up! Shut -- shut -- shut -- shut -- shut up! Reporter: Or the worried male nurse in "Magnolia. I know I might sound ridiculous like this is the scene of the movie where the guy's trying to get hold of the long lost son. You know, but this is that scene. Reporter: Today one critic said Hoffman had a rare ability to illuminate the varieties of human ugliness. No one else ever did it so beautifully. And he died in the prime of his life. He was 46 years old. Imagine for a moment what he could have gone on to do. Reporter: Among the the movies left unfinished, the final installment of "The hunger games." He died in his prime. A career and a life cut short. We lost Philip Seymour Hoffman. We lost everything he would give us for the next 20, 30, 40 yea years. The finest actor of his generation. And the drugs got him. Reporter: Tragically, he'll also now be remembered for the demons that drove him to an early death. I'm David Wright for "Nightline" in Hollywood.
This transcript has been automatically generated and may not be 100% accurate.