cinema history - What is the first instance of a disaster movie coming true?

Though not strictly a movie, there is the now infamous example of the pilot episode of the X-Files spin-off show, The Lone Gunmen.

Airing 6 months before the terrorist attack on 9/11, it depicts the hackers foiling an attempt by a shady organization to fly a plane into the WTC in order to catalyze a Mid-East attack.

Dodgy conspiracy theories aside, this is a prime example of the entertainment media prophesizing a real event/disaster.