Welcome to reality/nightmare
Some of us have been thinking about these problems for a LONG time - unfortunately, because some of the scenarios people talk about are VERY non-pc, and (lets face it) some of the people are nuts - these "survivalists" get a bad name
Unfortunately, what's happening in NO has proven some of their case - society HAS broken down in NO - now let's say there WAS no place to evacuate to? That is the worst case the "survivalists" talk about, and always gets the worst (and most) publicity
When you really watch what they spend MOST of their time talking about - it's how to be prepared to survive weeks to months without outside help.
CASH on hand helps in most scenarios, as there IS still an outside world, and it helps you "Bug out"
WATER (clean water) is crucial - let's really face it - the most critical shortage in NO right now is CLEAN water - sitting on your rooftop, if you have food and water may not be FUN, but it's survivable (in general). You have to figure on needing a MINIMUM of 1 gal/day/person, and better to have 2-3gals/day/person, and have a weeks worth - yes folks, figure on 20 gals/person - 7 as a minimum
Food - preferably stuff that does not need COOKING - you have 72 hours worth? Do you have a months worth of dry/canned food (can need cooking) in your house?
Do you know what hazards are in your area? Chemical plants? Do you live in a flood plain? Earthquake zone? Tornado Alley? Hurricane area (NYC is one - city is 3rd most at risk - after Miami and NO). Forest fires? (and we won't even discuss "the end of the world as we know it" (TEOTWAWKI) scenarios - the ones that give survivalists their bad rep)
Probably the most important thing is MIND SET - you're "Feeling Vulnerable" title is right on the mark - you are FINALLY aware of what a lot of folks have known all along. They (we) TRY to do things to mitigate our risk - and the awareness of the risks is the first step
You (and in my case I) may not choose to prepare for TEOTWAWKI - but I know I prepare for blackouts, ice storms (read the stories of the great NE ice storm of the 80s), hurricanes, etc
One thing this storm did was make me change some of my plans - My plans for a hurricane has always been "shelter in place" - I live 100 ft above sea level, 3-4 miles inland. Flooding will not be an issue. I've always planned on having my family hunker down, and I was going to go do my volunteer disaster work. My plans have stayed the same for a Mid Cat 2 or lower - above that? We bug out - I know exactly where we are going - 120 miles inland to a friends house. Once my family is there, and secure, THEN I will return to do my volunteer work