Beyond the Poseidon Adventure (original plot)

After the release of The Poseidon Adventure, Irwin Allen has conceived of a sequel that was different than the final product.

Plot
Unlike the actual sequel, the original plot would've been about the survivors trapped in a crashed tunnel train, while heading to testify the disaster. And they must escape.

Why It Was Cancelled

 * It would've been impossible to make a movie without the Poseidon.

Results

 * The script was rewritten.
 * The actual sequel would ￼received negative reviews, and poor box office reception.
 * Elements of the original plot would ended up in Daylight with Sylvester Stallone.