This is an amended Theory.
(First – to differentiate properly, I’ll refer to the two universes as Lost PRIME, which is where the story has taken place for the past 5 seasons, and Lost SIDEWAYS, as the executive producers have labeled the new continuity)
In Lost PRIME The Incident was never clearly defined. What was the Incident? According to “Dr. Marvin Candle”, a.k.a. Dr. Pierre Chang, in the Swan Orientation film, the Incident was an electromagnetic anomaly that caused a catastrophic event at The Swan construction site. Not very descriptive, right? Could they have been hiding something? Of course they were!
I suggest that The Incident was always the splitting of the Lost PRIME universe into the Lost SIDEWAYS universe in 1977.
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