Though it’s hard to imagine James Cameron's Titanic as being anything but one of Hollywood’s biggest hits, the film’s box office prospects weren’t looking very good before its release. Despite highly publicized production nightmares and budget problems, the 1997 romantic epic managed to turn things around when it reached cinemas—in a very big way. Here are six blockbuster movies that were expected to flop.

1. SNOW WHITE AND THE SEVEN DWARFS (1937)

Snow White and the Seven Dwarfs was Walt Disney’s first feature-length animated movie. In fact, it was the first animated film to have a running time over 80 minutes. Owing to the fact that it was the first of its kind, many people found it hard to believe that children would be able—or want—to sit still for that long, or that parents would be willing to suffer through more than an hour of an animated fairy tale. Hollywood journalists believed that it would be a box office flop, with some calling the animated film “Disney's Folly.” Even Walt Disney’s wife, Lillian, thought that Snow White was doomed to fail.

However, when it was released in 1937, Snow White immediately became a critical and commercial success. Walt Disney was later given an Honorary Academy Award (which was accompanied by seven miniature statuettes) for his work on the flm, which was "recognized as a significant screen innovation which has charmed millions and pioneered a great new entertainment field.”

2. STAR WARS (1977)

Before its release, Star Wars was considered a box office bomb waiting to happen. The problem? It looked too different from other sci-fi movies of the time. Fox executives didn’t have much faith in George Lucas' space opera, so only booked it into 40 theaters for its Memorial Day weekend opening.

“There’s an enjoyable irony to this,” Robbie Collin of The Telegraph wrote. “In 1977, Fox was convinced that Star Wars was going to be a flop because the damn thing was so unfashionable. In the mid-seventies, American cinema still looked like Taxi Driver and All the President’s Men, and all the available data suggested that audiences preferred their pictures realistic.”

Even Lucas was convinced that Star Wars was going to flop. To insulate himself from the possibly dismal box office numbers, he hopped a flight to Hawaii with Steven Spielberg, which is where the pair cooked up the idea for Raiders of the Lost Ark.

"It's a science fiction film,” Lucas told Stephen Colbert during a Q&A at the Tribeca Film Festival in 2015. “Science fiction films get a good old group of sci-fi fans. They'll go to anything the first week. Wait for a couple weeks, and you'll see what it's really gonna do. [Originally] nobody liked it [at the studio].”

3. TITANIC (1997)

Before it was released in December 1997, many film reporters were predicting that Titanic was going to sink. It had a disastrous production with numerous delays and a bloated budget of $200 million, the highest of any film at the time. The Los Angeles Times even began running a daily column called “Titanic Watch,” which chronicled every production delay and increasing budget concern for the massive film. When Titanic was pushed from its original summer release date to a December one, many in Hollywood felt that the epic movie could be a colossal flop.

“The likelihood that Titanic, the costliest film ever made, will delay its opening, previously set for the July 4 weekend, is sending ripples across Hollywood and turning the summer season into turmoil,” The New York Times reported.

The film, of course, ended up being a monster hit and held the top spot at the box office for 15 weeks straight. It didn't drop out of the top 10 until mid-June of the following year. It became the-then highest grossing movie of all time with $2.1 billion, not to mention 11 Academy Awards. "They were dissing it all around,” star Gloria Stuart said about its surprise success. "That happens in Hollywood.”

4. AVATAR (2009)

After the success of Titanic, James Cameron took a 12-year break from narrative features to make Avatar, another larger-than-life movie that used state-of-the-art technology. Like Titanic, Avatar had to contend with numerous delays, rewrites, and a ballooning budget. Studio executives and film reporters believed it would flop under its own weight because of its production woes, not to mention its three-hour running time.

“What we have with Avatar then, is the inverse phenomenon of Titanic,” said columnist Drew Magary just before the film’s December release date. “Titanic was expected to flop, and ended up crushing everything in its path. Avatar arrives heralded as the greatest film event in history. But all the 3D pterodactyls and giant robot exoskeletons in the world won’t help the movie if it ends up, you know, sucking. It’s impossible to know until you see for yourself, but it sure doesn’t look very promising right now.”

Once again, Cameron managed to prove his detractors wrong. Avatar quickly became a worldwide phenomenon, taking in just over $2.7 billion to become the highest grossing movie of all time (a record it maintains today).

5. INCEPTION (2010)

After the monster success of 2008’s The Dark Knight made Christopher Nolan Hollywood’s hottest director, he was given license to pursue any film project he wanted. He chose Inception, a mind-bending heist film based on Nolan’s imagination and starring Leonardo DiCaprio. Due to the film’s highly original story, studio executives were worried that audiences might not be onboard with Nolan’s “dream” movie.

"Nobody thinks it's a bad movie," an unnamed executive from a rival studio told Reuters. "The question is whether it's going to be the real breakout picture that everybody seems to think or just the darling of the east and west coasts and miss the rest of the country."

The feeling around the entertainment industry was that Inception would be a good movie, but too complicated for general audiences to be interested in or understand. While there was no doubt in Nolan’s talent as a director, few people thought that the film would make a profit, or that Warner Bros. would even recoup its $200 million investment.

“This film will be a major flop at the box office,” science fiction author Jason Sanford wrote in 2010. “My prediction is that this will be a good [science fiction] film which the critics will love, but which doesn't find a large audience because of its subject matter. Since Christopher Nolan is still Hollywood's golden boy and is working on another Batman movie, studios will overlook losing their shirts on this film. But that won't change the fact that Inception will be a flop.”

Inception ended up becoming a smash hit when it was released in July 2010, earning $825.5 million globally, and later winning four of its eight Academy Award nominations, including Best Visual Effects.

6. GUARDIANS OF THE GALAXY (2014)

While Marvel Studios is responsible for some of the biggest superhero movies of the last decade, Guardians of the Galaxy was positioned to be the movie studio’s first major flop—well before it was even released. It was a weird sci-fi adventure featuring characters that weren’t popular in mainstream culture (namely a talking raccoon named Rocket and a walking tree named Groot) and it starred actors who weren’t (yet) viable box office attractions.

“A movie about an unknown group of superheroes that includes a talking raccoon and a tree that's sort of a person won't be a box office hit no matter how many Marvel fanboys watch its trailer online,” wrote Daniel B. Kline of The Motley Fool. “With Guardians of the Galaxy, Marvel has the classic ingredients for a flop—perhaps not a huge one, but a failure compared to the superhero films the company has released since falling under the Disney banner.”

After it was released, the Marvel movie quickly became one of the highest grossing movies of the year, and launched Chris Pratt’s career into Hollywood stardom.