Shortly after the movie started, they and others noticed the emergency exit door to the audience's right swing open, spilling light from an outside lamp into the darkened theater.

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"It's one thing to be able to help people out of an emergency exit door, it's another to say they must weigh less than 130 pounds, as Pan Am and others might have done in times gone by, " says Kenneth Quinn, partner and head of aviation practice at the Washington, D.

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Mr Tessmer also said many people thought a door inside the nightclub, which gave access to the loos, was a possible emergency exit.

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