This is an option I do not recommend. There are cities with very large structures which COULD provide shelter. Abandoned steel mills, large gravel factories that are abandoned, missile silos, and warehouses all provide possible shelters. The “left Behind” books portrayed some survivors hiding in abandoned office buildings. I think that’s optimistic at best, but again, it also depends on the second seal and war.
Areas which have been devastated in warfare tend to be thought of as battlegrounds. When that battleground ceases to provide active resistance, the thought is that it is now neutralized, and merely awaits a mopping up operation as the armies turn to other threats. There were entire areas in France that German troops remained, unbothered by Allied troops while they moved forward to major areas. And again, once larger battlefields were neutralized, the armies would surge forward to deal with other areas… leaving a battleground.
If, as was suggested in the Left Behind fiction series, Chicago were to be demolished by air raids, there would still be mostly undamaged structures remaining one could shelter in. I personally wouldn’t recommend that in Chicago, as most tall buildings there are steel skeletons with a glass exterior to tighten it together. With the integrity of the glass violated, the buildings become somewhat hazardous.
The one “Shelter in place” option I do not advocate whatsoever is the one being advocated by post-trib believers, that of simply fortifying your home to prevent looters from getting in. See, the Antichrist will have a lot of military technology at his disposal, and anyone who’s been party to a door breaching knows there’s large rams that can smash open a fortified door. If the door is too stout for that, some det-cord applied to the door – or hey, maybe some C4 will simply cave in your door nicely.
The breaching team tosses in a flash bang after the door is blown off its hinges, and then they fan into the room, applying three round bursts to everyone in the room.
So if your plan to avoid capture by the antichrist is to set a 4X4 between the door and the bottom step in your stairway, trust me when I say that the 4X4 will slow them down ten seconds. Then you’ll be dazzled by the flash-bang, and everything should go black immediately after that as they shoot you. Or they could drag you outside and shoot you in the back of the head. Or simply drag you to their holding area, then out to the guillotine.
That kind of sheltering in place is quite simply going to end in failure and death. I don’t recommend it.
Okay, if you’re choosing the “LA Warehouse” method, that may possibly work, but I’m not recommending it for a long period of time. You don’t think that once the Antichrist institutes the “number of the beast” policy that they’re not going to go door to door to see? You don’t think that they’re not going to fly by the warehouse district in a helicopter looking through infrared to see where unexplained heat sources are coming from?
It may work for a little while, maybe as much as a year, but eventually, it’s going to be a bad idea.