Well, Margaret got seriously injured and almost died shooting this scene. It wasn’t just smoke and mirrors, trust me.
Hamilton had excellent chemistry portraying her role of the Wicked Witch of the West and gave an amazing performance, but some other chemistry might have been fatal.
Namely, her makeup was petroleum based and the sparks from the special effects reacted together with the flammable chemical from her makeup causing it to catch fire. Margaret ended up suffering from third degree burns to her hands and second degree burns to her face.
This accident was actually caused by the negligence and even arrogance of the film crew. One of the directors insisted on Margaret being seen one last time before the explosion making the famous puff of smoke goes off. The trap door through which the actress was supposed to go when she disappears didn’t work properly, Margaret couldn’t escape on time and her makeup started to burn.
She spent several weeks recuperating in the hospital, but when she got out Margaret stoically decided not to press charges.
“I won’t sue, because I know how this business works, and I would never work again. I will return to work on one condition – no fireworks!” she said in a statement.
All in a day’s work.