Factual error: When Xander's thugs are taking the Phantom up to the roof to do away with him, he breaks away and ducks into the machinery room for the elevator. In the scene the door of the room is lockable from the inside only. This door should be lockable from only the outside.
Factual error: When the policemen are shooting at the Phantom in the park, bullets make little explosions when they hit the trees, as if it was metal.
Factual error: When the car pulls away from the front of the "New York World History Museum", you can see palm trees reflected on the car, revealing that "New York" was actually filmed in California.
Factual error: Throughout the movie, any cigarettes smoked are filtered. The movie is set in the 30s-40s. The first filtered cigarettes were from a company called Lorilland for their "Kent" brand in 1952.
Chosen answer: The explosions from the skulls and the weapons on the island caused the volcano to erupt.
LorgSkyegon