It's not often that you get a warning before a natural disaster. Or even if you do, many people fail to understand the impact it's going to have. For me, there's no greater risk than being unprepared. I've lived through military takeovers, flooding that cut me off for months, and there's one thing that I always keep with me now. My bug out bag.
But there's a few caveats. Because what I packed in mine while I lived in the city requires a little bit of a different approach to the one I have now on my homestead. As big cities are their own beast, and if you want to be prepared to escape, you need to plan accordingly.
Here's what I recommend keeping in yours:
In a big city the biggest concern is the population. There are always bad people, but the concentration in an urban environment means you'll get more "bad guys" and you need to be able to protect yourself. My urban kit includes not only pepper spray, but far more ammunition than I'd normally pack for my handgun. Because I want to be able to protect myself, no matter what. And there's so many people surrounding you, everyone facing the same crisis. I'd forgo the long rifles as they draw too much attention, get a concealed carry and be non-conspicuous.
With the amount of buildings for shelter, I'd skip the tarps and camping gear, instead focusing on dark and warm clothes you can use to move around without drawing attention at night. Avoid anything with bright colors and have thick black garbage bags and duct tape you can use to black out the windows of where you're staying. Oh, and invest in a decent padlock too. You may be able to use it to secure a door at night and get a good night's sleep while you're trying to escape the city.
Sturdy boots for hiking
After a crisis like an earthquake, there is going to be rubble and broken footpaths everywhere. You need a decent pair of boots so you can stay on your feet, hike to a safe area, and not worry that you're going to roll an ankle or drench your feet in a puddle. Invest in a good pair of hiking boots that will keep your feet warm and dry, have non-slip soles and don't forget to keep a couple of changes of socks in your urban bug out bag. Just in case.
With smoke, dust, and the potential for leaking gas pipes a major concern, you need a way to ensure you're not breathing all this bad air. Buy a disposable respirator and keep it in your urban bug out bag so you're ready. Just make sure whatever you buy is rated to stop you breathing these harmful gases when you're trying to escape. It could make all the difference.
Torches for the buildings
If you're using abandoned buildings, without power the interior of these (especially basements and stairwells) is going to be pitch-black. Pack a headlamp, a backup flashlight, and enough backup batteries to keep you going for at least 72 hours. I've actually opted for a solar-powered headlamp just in case I get stuck so long - as I can get to a rooftop for a couple of hours it'll get enough juice to stay "on" the entire night.
Food that doesn't need to be cooked
Again, the giant press of people in a city is your biggest risk. And starting a campfire to cook up whatever it is you've got your hands on to eat is a big red flag. The smoke, light, and smells will alert anyone in the nearby area to what you're doing. Instead, pack ready to eat meals that are high in calories. Protein bars, dried fruits and nuts, and even a couple of MREs are a much better choice, as you can prepare and eat with a minimum of fuss and get back to survival.
Breaking and entering gear
It's not something I like to promote, but in an urban environment you need to be able to get into secure areas to stay safe. Buy a lock-picking kit and learn to use it, and it may even be worthwhile carrying a crowbar or a pair of lock-cutters. Use these to open up secure places to stay until you're able to escape the city. Oh, and remember to always have an escape plan. Like a length of rope, that you can shimmy down from a second-floor window in case someone comes in the front door.
Finally, pack the rest of the kit with the basics you'd have otherwise. Fire-starting tools. A first aid kit. A water filter and a bottle to carry a little with you. And a means of staying in touch with the other people in your group. We've already got our live communication sorted, and a plan if we're separated from everyone else and we need to re-connect. Oh, and bug a decent bug-out-bag. Something that fits comfortably on your back, and you're able to carry around (when it's packed full of gear), with little fuss. You want to stay agile and, on your feet, when you're bugging out.
In a crisis you never know what's going to happen, so it's important to be prepared. And you'll definitely need a few different pieces of gear in your urban bug out kit, so make sure you've got these packed so you're ready for anything when the SHTF.