The 1977 east coast summer blackout. I was watching THE ISLAND OF DR MOREAU-77- BURT LANCASTER in a New York theatre when suddenly the film went dead. For a few minutes me and others in the theatre thought it was the projectionist . But it was not the whole city was dark. A week later i went back to see it again this time uninterrupted.
During a screening of EARTHQUAKE in Sensurround, the subwoofers dislodged some foam tiles from the suspended ceiling and they rained down on the audience during the first tremor. It was too realistic for some audience members who proceeded to scream hysterically.