Front Custom CoversEven though it's been 25 years since the release of "The Bodyguard" (on November 25, 1992), no doubt the final high note in Whitney Houston's "I Will Always Love You" is still ringing out somewhere in the stratosphere.

The romantic thriller made the already beloved singer into a movie star as well, became the second biggest hit of 1992, and spawned the biggest-selling soundtrack album of all time.

Still, as often as you've watched Kevin Costner rescue Houston, there's much about "The Bodyguard" you may not know, from it's 16-year journey to the screen, to the real-life tragedies behind the production.

1.Lawrence Kasdan wrote the screenplay way back in 1976, years before he became famous as one of the writers of "The Empire Strikes Back" and "Raiders of the Lost Ark" and the writer-director of "The Big Chill." In fact, it was his first screenplay.

2. Warner Bros. bought the screenplay as a vehicle for Diana Ross and Steve McQueen, but the project stalled over concerns that audiences wouldn't warm to the interracial romance. (Also, both stars supposedly balked at being billed second.) A later version of the project, which would have starred Ross and then-boyfriend Ryan O'Neal, also stalled.

3. The script finally had a chance to reach the screen when Costner, who'd appeared in several Kasdan projects, came aboard as producer and star. He wanted Houston to play pop diva Rachel Marron opposite his security expert, Frank Farmer, but she'd never acted before and was hesitant to make her debut in such a large role opposite an A-list actor. "I was scared. It took me two years to decide to do it," she said in 1993. "I kind of waited too long for Kevin. I think it got on his nerves. He called one day and said, 'Listen, are you going to do this movie with me or not?' I told him about my fears. I said: 'I'm afraid. I don't want to go out there and fall.' And he said: 'I promise you, I will not let you fall. I will help you.' And he did."

4. Many critics noted at the time that the movie presented an interracial romance without making any big deal about it. Actually, it was a coincidence that all the casting ideas for the film had involved interracial couples. In fact, there was no mention in the script of the characters' races. Costner recalled in 2015 that he felt casting Houston was a no-brainer. "It didn't seem to me to be a brave move at all. I thought she was the cutest girl I've ever seen," he said. "I couldn't imagine anybody that didn't want to kiss her."

5. In a creepy life-imitates-art aside, Houston noted at the time that she'd received death threats just like Rachel had. "I've had someone write me a letter, somehow it got to me," Houston said at the time of the movie's release. "It said that they were going to shoot me in the last couple seconds of my show. And they weren't going to miss."

6. Recognize Rachel's mansion? It's the same lavish estate used in "The Godfather" as the home of movie mogul Jack Woltz, the guy who wakes up to find his horse's head in his bed.

7. Recently engaged to Bobby Brown, Houston suffered a miscarriage during the shoot. "It was very painful, emotionally and physically," she told Barbara Walters in 1993. Nonetheless, she added, "I was back on the set the next day" Shortly after the film wrapped, Houston and Brown were married. She conceived again and gave birth to daughter Bobbi Kristina in 1993.

8. One crew member was killed during the shoot. Bill Vitagliano, a 33-year-old driver, was crushed in an accident involving two lighting equipment cranes.

9. In the movie, Frank Farmer's favorite film is Akira Kurosawa's classic "Yojimbo." Translated into English, the Japanese title means "bodyguard."

10. "The Bodyguard" wasn't the first time that "I Will Always Love You" was heard in a movie. Martin Scorsese had also used the song on the soundtrack of 1974's "Alice Doesn't Live Here Anymore," shortly after Dolly Parton composed and recorded it. When Parton starred in 1982's "The Best Little Whorehouse in Texas," she added it to the score for her character to sing. The song went to No. 1 on the Billboard Hot Country chart both times, making Parton the first singer ever to to top the chart twice with the same song.

11. In 1974, Elvis Presley wanted to cover the song, but because his manager, Col. Tom Parker, demanded that she grant Elvis half the publishing rights, Parton refused. She was heartbroken about having to turn down the King. "He would have killed it," she mused, years later. "Then when Whitney [Houston's version] came out, I made enough money to buy Graceland."

12. Of course, it's Houston's monumental cover that most listeners remember. It was country fan Costner who picked the song for the movie's emotional climax.

13. Initially, Houston was supposed to sing a cover of Jimmy Ruffin's "What Becomes of the Brokenhearted," but the filmmakers found out the song was going to be used in "Fried Green Tomatoes." Costner not only came up with the last-minute replacement, but also insisted that the song open with Houston's voice unaccompanied by any instruments. "I need it to be a cappella because it shows a measure of how much she digs this guy," Costner recalled saying, "that she sings without music."

14. Director Mick Jackson's initial cut of the film displayed few romantic sparks between the two leads. "There was no chemistry," Jackson said. "They looked like a couple of pals passing the time of day instead of the torrid lovers they were supposed to be." But Costner, who had final cut rights, kept his word that he wouldn't let Houston look bad. He oversaw an edit that trimmed Houston's dialogue and gave her more close-ups. That did the trick.

15. Made for a modest $25 million, "The Bodyguard" earned back $122 million in North America and $411 million worldwide. Globally, it made more movie than any other film in 1992 except "Aladdin."

16. Houston's version of "I Will Always Love You" sold 12 million copies, making it the best-selling single ever by a woman. Her recording topped Billboard's Hot 100 chart for a then-record-breaking 14 straight weeks. It also sold millions of downloads in the days after Houston's death in 2012, for a total of 20 million units sold. "I knew I had sung the s**t out of it," Houston said in 1993. "But I had no idea that that record would sell so much, so fast"

17. The "Bodyguard" soundtrack sold 17 million copies in the United States and 45 million around the world. The album was nominated for four Grammys and won three, including Album of the Year.

18. The Academy nominated "The Bodyguard" for two Best Original Song Oscars, for "I Have Nothing" and "Run to You."

19. Costner claimed in 2012 that he'd been developing a "Bodyguard" sequel that would have marked Princess Diana's acting debut, in a semi-autobiographical role, and that her tragic 1997 death came within days after he'd received an early draft of the script.

20. A stage musical version of "The Bodyguard" was mounted in London in 2012, featuring well known songs from the film as well as several other Houston hits. Eventually, the production toured the United States.

21. In 2011, Warner Bros. announced it was developing a "Bodyguard" remake, one that would acknowledge how much easier stalking is now in the social-media era. The studio wanted Rihanna for the lead, but the pop star turned the project down, saying she wanted to play anything but a singer. "I hate it when singers do singing movies all the time, because you can never look at them as anybody else. I want to play a character," she said. "My whole life is playing Rihanna; being a singer won't be a stretch for me."

22. At Houston's funeral in 2012, Costner gave a eulogy, saying of her "Bodyguard" performance, "You made the picture what it was. A lot of leading men could've played my part, a lot of guys could've filled that role, but you, Whitney, I truly believe that you were the only one that could've played Rachel Marron at the time."