Monderno has an extensive rundown of what you need to have with you everyday to survive an urban disaster.
The best way to be prepared for most people is going to be to build an Urban EDC Kit, sometimes called an Urban Survival Kit (USK). The reason we won’t focus as much on the survival aspect of the kit is because in your vehicle you should have a 72 hour survival kit, which is of course built to keep you alive for a minimum of 72 hours. If a disaster were to strike while you are at the office, odds are pretty high that you will at least be able to stop by your vehicle if you need to, even if you can’t get in and drive home.