I know that I have mentioned this before in other threads, but think of your gear in layers. Layer 1 is what you need to survive (basic physical survival, appropriate to your situation) and is carried on your person. Your real Every Day Carry. A cell phone is included in this in my opinion, as it can help to prevent, avoid or resolve most situations. Tools that are commonly carried by some of us may be illegal in other areas, so check to make sure. A Swiss Army Knife without a locking blade (which generally have shorter blades than the locking ones) will have multiple tools and are usually legal, even in New York City. The small multi-tools are usually legal.

Layer 2 is what you need to get home or to a safe area, which may take a little more time and effort. A small backpack, fanny pack or other bag with maps, water (because it is difficult to carry in your pocket), shelter (keep you dry and stop the wind, maybe insulating as well), power for your communications, non-technical signaling (something bright and visible that is recognizable as an emergency signal), some snacks (your brain works better with some water and energy, improving your decision making), maybe a more substantial tool or tools that are not suitable to carry in your pocket, same with light (maybe a small lantern, a more powerful signaling light).

Layer 3 is in your vehicle, on your bike or in your office or other safe area on your route. I would prep your place of work, know what resources or safe areas may be available along your route, and prep your house. This is more long term, shelter in place for more than a few hours. Water, shelter, food, first aid, water purification, decently comfortable sleeping gear. Consumable supplies for about 3 days.

Every individual's situation will be a little different. Hurricanes, earthquakes, floods, tornadoes; they happen. There are many other, less common, potential emergency situations that you can prepare for, but generally if you can survive for 3 to 5 days you should be able to handle most situations until you can either receive help or get to help.

Think about what is most likely to happen, and what is most dangerous or catastrophic. What will you need to do? Where will you need to go? What will help you accomplish your immediate goals? If you are on the subway, will you need to evacuate or stay in place until rescue? Is it even possible to get out? Are you very familiar with the areas you travel through on the bus? Do you know alternate routes, what are the potential threats and safe areas along those routes?

Your brain is your most important and effective survival tool. The time you spend thinking through potential scenarios and gathering information is priceless.