It's the same way you approach your business in general. How can I solve a problem for someone else? You hear this over and over from the most successful individuals in business and in life. Solve problems for people and you will make money. The bigger the problem the more money.
Real estate is no different. As an investor you solve problems (whether you realize it or not). As a flipper you find unlivable houses and improve them to create a home for someone. As a landlord you provide a home for someone who may not be in a position to purchase or have no desire in owning a home but needs a comfortable, safe shelter. The most successful investors are problem solvers.
The first step is to do discovery. Understand why someone is interested in selling their property vs. fixing it and what their specific situation is. What are their needs and motivations that are unique to them? Obviously with Harvey & Irma you can make some educated guesses (no insurance, desire to move somewhere else, etc.), but ultimately you need to understand their situation and what they need, why they may want to sell, how you can structure a deal, and what the impact will be for both parties.
Once you understand that you can then evaluate if there is an opportunity as an investor and how to best structure an offer that benefits both parties. There may be a great opportunity or not. Recognize that you are ultimately working with people and realize they may have lost everything. How you approach and ensure you are actually understanding what their needs are and motivations will enable you to ethically find opportunities.