Why Jurassic Park 2's T. Rex Rampage Through San Diego Was Added Just 6 Weeks Before Filming

We know the original King Kong movie exists in the Jurassic Park universe, as evidenced by the sardonic comment made by Ian Malcolm (Jeff Goldblum) in the first movie, so why would anyone think bringing a large and uncontrollable beast to the mainland, least of all a heavily populated city, is even a remotely good idea?

Well, human arrogance, greed, and a blatant lack of common sense — particularly on the part of John Hammond's nephew, Peter Ludlow (Arliss Howard) — are major contributing factors. Then there's the behind-the-scenes explanation: Director Steven Spielberg thought the visual of a T. rex rampaging through the streets of San Diego would look really cool onscreen, and he was right. What you might not know, is that The Lost World's third act set piece wasn't added to the script until six weeks before filming began.

Why the T. rex's Lost World rampage in San Diego was a last minute addition

In Jurassic Park: The Ultimate Visual History, Spielberg reveals that he initially planned to helm a third movie in the franchise, which "was going to be about the dinosaurs getting loose in the world" —  à la what eventually happened in the Jurassic World movies. By this point in his filmmaking career, however, the celebrated storyteller had already decided to focus on deeper, historical-based projects (think Schindler's List and Amistad) and with Saving Private Ryan looming on the horizon, he opted out of making another Jurassic blockbuster, ultimately handing the reins over to Joe Johnston for the 2001 trilogy capper featuring the return of Sam Neill's Alan Grant.

With that said, Spielberg simply couldn't resist an opportunity to dabble in all-out dinosaur mayhem on the mainland and asked Lost World screenwriter David Koepp if they could just "make the entire third movie the third act of the Lost World." To that end, director and writer put their heads together at Spielberg's home and came up with the new conclusion over the course of a single day, a little over a month before cameras were slated to roll.

"That was exciting," Koepp says in the book. "He was like, 'I think we've got to go further.' He wasn't comfortable just repeating a lot of the climactic beats of the first movie. We've got to give them something new." San Diego was chosen as the backdrop for the daddy T. rex's post-nap frenzy because of the port city is "the closest point of the United States [from Costa Rica]," Koepp explains. "And also San Diego is ... associated in our minds with SeaWorld and the zoo and animal attractions."

While this eleventh hour addition meant more a lot more work for the talented wizards at Industrial Light & Magic, Visual Effects Supervisor Dennis Muren — who would end up nabbing an Oscar nod for his work on the 1997 sequel — was quite pleased with the end result. "It gave you what you wanted to see," he proclaims. "You'd already seen dinos chasing people in jungles ... Getting a T. rex to grab a car and filing it through the air and roaring at city lights — it was just a whole different environment."

The original Jurassic Park trilogy is now streaming on Peacock alongside Jurassic World, Jurassic World: Fallen Kingdom, and Peter Jackson's 2005 remake of King Kong.