Imagine what it would be like to meet a Tyrannosaurus Rex face-to-face. Pretty scary right? Well luckily that can’t happen, but for Joseph Mazzello and Ariana Richards they got to enjoy that lovely experience. During the scene in Jurassic Park when Tim and Lex Murphy (Mazzello and Richards respectively) were in the truck and the T-Rex went through the roof, the glass was not supposed to break. Their screams of fear were genuine.
That’s not the only time the T-Rex animatronic caused problems on set. Occasionally, the rain would cause the T-Rex to malfunction. Kathleen Kennedy, the producer, said “The T. rex went into the heebie-jeebies sometimes. Scared the crap out of us. We’d be, like, eating lunch, and all of a sudden a T. rex would come alive. At first we didn’t know what was happening, and then we realized it was the rain. You’d hear people start screaming.”