Fifty years ago this Sunday, Paula Strasberg was sitting in her apartment on Central Park West when she got a horrible phone call. Her friend and pupil Marilyn Monroe was dead.

Strasberg had been with Monroe just days before in Los Angeles, coaching her through her performance on what ended up being her final movie, "Something's Gotta Give." The coaching taxed Strasberg's strength, which was already ravaged by cancer that she refused to discuss with even close friends and that ended her life soon after, so she flew back to New York for a few days of rest. She knew Marilyn wasn't doing well -- but she had no idea just how badly.

Strasberg's son John, one of the few people alive who knew Monroe well, recalls that his mother was wracked by guilt in the days that followed the awful revelation.

"My mother was going, 'Oh, it's my fault, I should have been there with her'. One had the sense of taking care of Marilyn. She liked that -- and she also elicited it from people," he told The Huffington Post.

Paula was, of course, far from alone in her grief. Monroe's death from a drug overdose at the age of 36 was a personal tragedy -- the inevitable ending to a life that was wracked by depression, abuse and drug addiction. But it was an equally large tragedy for Hollywood. The movie industry lost years, if not decades, of work from one of its brightest stars.

Monroe was so tortured the last few years of life that she was in no shape to get her career together. Even if she had survived the night of Aug. 5, 1962, she might have ended up in a similar situation a few months later. And many of the factors that led her to abuse drugs were tied to her personal life, not her career. But assuming for a moment that she was able to find health and happiness -- what might have she done for the next 30 or 40 years of her career?

It's a question that has haunted John Strasberg, 71, for a half a century. He knew Monroe for about eight years, when he was a teenager and she worked with his parents, Paula and Lee Strasberg, who ran the famed Actors Studio in New York. The Strasbergs played as big a part as anyone in Monroe's career during its final phase.

Monroe went to the Strasbergs in search of respect. She was tired of being known as nothing more than a pretty face, and eager to be taken seriously as an actress. John Strasberg said his father would talk to Monroe for hours and hours, alone in their apartment. Despite Paula's best efforts to eavesdrop on their conversations, no one ever knew what they discussed. But John Strasberg said that those talks and Monroe's work at the Actors Studio convinced his father that she had it in her to become the kind of dramatic actress she hoped to be.

"My father, who adored her and thought she was potentially one of the great actresses of her generation, thought that she could play all the great parts -- Blanche, in '[A] Streetcar [Named Desire],' for example," he said.

Making better movies was certainly a central ambition in the last years of her life. She was emboldened by her work with the Strasbergs and by the good reviews she got for her roles in "Bus Stop" and "Some Like It Hot." Monroe and Lee Strasberg talked for years about collaborating on an adaptation of Somerset Maugham's "Rain," which would be directed by Strasberg and star Monroe as protagonist Sadie Thompson. They also discussed adapting Dostoevsky's "The Brothers Karamazov," with Monroe as Grushenka, a beautiful woman who inspires a character to murder his father. There also were rumors of a movie about Freud.

Yet Sarah Churchwell, author of 2004's "The Many Lives Of Marilyn Monroe," noted that Monroe's movie choices were severely limited by her contract with 20th Century Fox studios, headed by the dictatorial Darryl Zanuck.

"He was completely contemptuous of her," she explained. "People forget how much power the studio heads had in those days. He was giving her garbage all the time because he thought she was worthless."

It's also unclear whether Monroe had the skills to master the kinds of dramatic roles she yearned for.

John Strasberg, an actor and acting teacher himself, thinks Monroe was an indisputably "brilliant comedian," who created the "dumb blonde" archetype and played it better than anyone else. But he also said she relied too much on his mother's coaching when she tried to stretch beyond that. He thinks that in the best-case scenario, Monroe would have spent the rest of her career pursuing romantic comedies like "Some Like It Hot" -- and avoiding both dramas and bad comedies like "Something's Gotta Give."

But it seems likely that Monroe's movie career would have lasted only a few more years, even in the best of circumstances.

"Back in those days, women, after a certain age, just weren't cast in movies," Strasberg said. "Bette Davis was the first one to fight through the prejudice about how women should look in movies and playing leading roles; she had won Academy Awards, but she couldn't get a job, so she put out ads in 'Variety' and the such. Whether Marilyn could have done that, I don't know. Certainly there was the possibility of that."

Churchwell also noted that Monroe died just before Hollywood started to shift away from the studio system and toward the wild culture of the 1970s, which was hard on many actors of Monroe's generation.

"I'm struggling to come up with one contemporary of Marilyn's who made any movie in the 70s. There wouldn't have been those roles for her -- she would have had to go do something else," she said. "It's very difficult to imagine her suddenly making films with Warren Beatty."

Monroe might have elected to try acting on the stage in New York. Much of her training at the Actors Studio was geared toward theater, and Strasberg said Monroe always felt more comfortable in the bustling, relatively anonymous world of New York than celebrity-obsessed Los Angeles.

Joyce Carol Oates, who in 2001 wrote "Blonde," an novel about Monroe, believes the stage offered Monroe's best chance of salvation.

"My belief about Marilyn Monroe is that if she had only resisted returning to Hollywood, to make such an egregious movie as 'Let's Make Love,' but had remained in NYC in association with the Actors Studio, she might well have had a stage career as a serious mature actress; she might even be alive today," Oates wrote in an email to The Huffington Post.

Strasberg once performed a scene from "A Streetcar Named Desire" with Monroe and found her very charismatic. But he isn't sure Monroe would have been able to sustain a nightly job in theater.

"Could she have held herself together on that daily basis? Would she have had that kind of discipline -- which obviously would have come from having enough love for what she was doing … I just don't know, because I never saw her do it," he said.

Churchwell added that Monroe was plagued by debilitating stage fright, even on movie sets, so she would have had to address that with a qualified therapist before tackling the theater in a serious way. If Monroe had been able to do that, Churchwell noted, she might have also started a one-woman act in Las Vegas, as her contemporary Debbie Reynolds did.

Then again, Monroe also might have decided to leave acting altogether. In her last interview, she said, "It might be a kind of relief to be finished."

Churchwell pointed out that Monroe was not, in 1962, in a financial position to retire -- the actress had been "vastly underpaid by contemporary standards of her peers" for most of her career. (Especially unjust considering how much money others make from her image to this day.) It was only in her last contract with Fox, signed less than a month before her death, that she received $500,000 per movie.

And if she had survived the night of Aug. 5, finished "Something's Gotta Give," then made enough movies to build a good-sized nest egg -- what then?

"She had seen women like Betty Grable bow out gracefully, say, 'I've had my time, and now it's time for something else'," Churchwell said. "So I don't think it was difficult for Marilyn to imagine that."

If she had lived, Monroe would have been 86 this year.

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  • "THE MISFITS" (1961)

    Roslyn Taber

  • "LET'S MAKE LOVE" (1960)

  • "SOME LIKE IT HOT" (1959)

    Sugar Cane Kowalczyk

  • "THE PRINCE AND THE SHOW GIRL" (1957)

    Elsie Marina

  • "BUS STOP" (1956)

    Cherie

  • "THE SEVEN YEAR ITCH" (1955)

    The Girl

  • "THERE'S NO BUSINESS LIKE SHOW BUSINESS" (1954)

    Victoria "Vicky" Hoffman.

  • "RIVER OF NO RETURN" (1954)

    Kay Weston

  • "HOW TO MARRY A MILLIONAIRE" (1953)

    Pola Debevoise

  • "GENTLEMEN PREFER BLONDES" (1953)

    Lorelei Lee

  • "NIAGRA" (1953)

    Rose Loomis

  • "MONKEY BUSINESS" (1952)

    Miss Lois Laurel

  • "DON'T BOTHER TO KNOCK" (1952)

    Nell Forbes

  • "WE"RE NOT MARRIED" (1952)

    Annabel Jones Norris.

  • "CLASH BY NIGHT" (1952)

    Peggy.

  • "LET'S MAKE IT LEAGAL" (1951)

    Joyce Mannering.

  • "LOVE NEST" (1951)

    Roberta "Bobbie" Stevens.

  • "AS YOUNG AS YOU FEEL" (1951)

    Harriet.

  • "HOMETOWN STORY" (1951)

    Iris Martin.

  • "ALL ABOUT EVE" (1950)

    Miss Claudia Caswell.

  • "THE FIREBALL" (1950)

    Polly.

  • "THE ASPHALT JUNGLE" (1950)

    Angela Finlay

  • "LOVE HAPPY" (1949)

  • "LADIES OF THE CHORUS" (1948)

    Peggy Martin.

  • "DANGEROUS YEARS" (1947)

    Evie.