Actually a few years back we got some new light on the trib.
According to the GB, since the trib in 1st century Jerusalem occured in 2 stages so it will be with the Gtrib.
2 stages you ask?? 66 AD romans come and the trib starts *get ready for new light* then the days of the trib were 'cut short' for 'flesh' or christians to be saved when the Romans unexpectedly left. Now enter 70 AD and they return and sack Jeru.Salem.
So in our time the discusting thing will first destroy BTG, this corrisponds to the first 'phase' of the trib on Jerusalem. Then the discusting thing will turn on gods peeps dwelling in security. At this time Michael will stand up and fight for his peeps. The second stage is HARMAGEDDDDDON
I dont think many witnesses have the same idea of the trib *concentration camps and the like* that they had in times past. I think the general idea is from the liturature that if you make it to the second stage you are home free and assured protection by Jehovah... er Mike... Um well anyhow. this is the ref to the new light.
2/15/95 WT Saved Alive Through the Great Tribulation studly article