Urban EDC.

To me, this is your basic kit list:

Money.
Mobile phone.
Water.
Snack food.
Torch.
Head torch.
Non-locking knife.
Multi-tool.
20' 550 cord.
Waterproof.
Lighter.
Small compass.
Carrier bag.
Garbage bag.
Day sack or haversack.

Now to explain:

Money. Always carry some cash. If you can still use your credit/debit card's then great. If not, a £100/$100 will go a very long way if spent carefully.

Mobile phone. Every day use + emergencys. Get one with a radio built in. Always as good idea if thing go pear shaped.

Water. A couple of half litre bottles. Dehydration is always an issue. It's amazing how much you sweat moving around people.

Snack food. If you can buy a hot meal then great. If not have enough calories on hand to stave off that low blood sugar feeling.

Torch. Hand sized L.E.D. City's have all sorts of dark and unfriendly corners. You may have to compromise between power and run time.

Head torch. Always a good idea. I've lost count of the number of times that I needed a torch and both hands!

Non-locking knife. Tends to upset those of a nervious disposition some what less than a locking/fixed blade. Even presuming that carrying the latter is legal for you.

Multi-tool. Your choice. One thing I will say: The Victorinox multi-tools are a lot better for urban use than Leatherman, Gerber et al. Tougher, better tools.

20' 550 cord. Don't have to explain that one do I?

Waterproof. Getting cold and wet is for idiot's. It does not need to be state of the art. Basic, packable will do.

Lighter. Ditto.

Small compass. It's very easy to get turned around in a city. Most city A to Z maps are orientated north up. Being able to sort out which way your facing is always a good start.

Carrier bag. Sit on it, turn it in to a waterproof hat. Carry your shopping in it.

Garbage bag. Ditto.

Day sack. Need some thing to carry things in.

Other thing's you might find useful are:

Electricians tape.
Duct tape.
Cable ties.
Note pad.
Couple of pens/marker pens.
Spare batteries.

Dress to survive, not to arrive. At least on your outer layers. Presume that you are going to miss the last bus or train home. Which means a night sitting on your bag, in the rain. Huddled under the garbage bag.
_________________________
I don't do dumb & helpless.