There was a scene in Ashok Thakeria's "Dhamaal", directed by Indra Kumar, in which actors Riteish Deshmukh, Arshad Warsi, Aashish Chowdhury and Javed Jaffrey were required to be atop a broken bridge at Borivalli National Park. Now, as if that wasn't risky enough, there was a family of four-five huge snakes resting under a few boulders right near the bridge. The reptiles were discovered when the camera was rolling, hence, the actors had no clue about the danger. A few lightmen kept guard while the shot was taken undisturbed.
According to a source, the snakes were perilously close to the
actors and had they made the slightest movement, the camera would have
caught a different drama altogether. But had the actors known
beforehand about the snakes they would have created a drama anyways. So
all's well that ends well.