A Natural Disaster may not be the reason you have an Underpayment Penalty.
Review the calculations on Form 2210, Underpayment of Estimated Tax.
In TurboTax Online, you will need to pay for your return and then you will be able to review the form in the PDF copy of your return that you can print or save to your computer.
Some reasons for an Underpayment Penalty may include, a new employer that is not withholding enough Federal Tax from your wages, a large cash distribution from a retirement account where not enough Federal Tax was withheld, Capital Gain income from selling an investment that is not a normal part of your income, or Self-Employment income.
Since we can't see your return in this forum, here's more info on Form 2210 to help you.