"They" are the ones in the watch towers with the telescopes and seismographs, and all the high tech equipment registering changes in the earths movements.
If these high tech sensors registered movements of an impending disaster..... perhaps that predicted Tidal Wave from La Palma....or an impending caldera blast from Yellowstone....or nuclear missles being fired from another country...
do you think they would really tell us?
Would they not simply shrug and say "there's nothing they can do about it anyway" and just keep quiet?
Would they not look ahead and say "if we evacuate them, it will be like Katrina all over again and they will become a responsibility to an overburdened system that cannot provide" and simply keep quiet?
If we were days or hours away from a cataclysmic disaster...would "they" tell us?
Do you think if they wanted to tell us...and we had half a chance...that "they" would be silenced by the Powers That Be?