I’m guessing Civil War. It discounts the possibility of a war, external, or pandemic.
9:14: saying to the sixth angel which had a trumpet, Loose the four angels which are bound in the great river Euphrates.
9:15 And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men.
I’m guessing the Rapture Departure coming soon will disappear 50 to 80 million who believe Jesus is Whom God sent for their salvation. That event will so devastate the country that perhaps 80 to 100 million will die soon after from disease, starvation, murders and suicides. Large cities will become death zones.