9. Matthew Vaughn Almost Drowned The Cast & Crew - Kingsman: The Secret Service
Director Matthew Vaughn is no stranger to tough productions, having started shooting X-Men: First Class just 10 months before it was released in cinemas, yet even the most studious, practical and prepared of filmmakers eventually ends up relying on modern technology.
And doing so gave Vaughn quite the hellish first day shooting the original Kingsman, as the first sequence to be shot was the memorable water training scene, which required exhaustive planning and rehearsals to execute.
The set was computer-calibrated in order to be effortlessly lowered into various depths of water quickly and safely, but the computer malfunctioned, immediately plunging an unsuspecting cast and crew into 20 feet of water.
In Vaughn's own words, "Cameras, sound guys. Guys were in waders full of water, panic, everyone diving in, and pulling people out. Those actors weren't acting, they were absolutely terrified. It was awful for the first day of filming."
Thankfully nobody was injured and the rest of the shoot reportedly ran smoothly, though a first day where your employees genuinely fear they're about to drown is about as terrible as it gets. Well, almost...