When Hurricane Katrina hit Louisiana and Mississippi a year ago, thousands of people lost their houses, possessions and even, tragically, loved ones. They also lost work. Many have relocated to cities such as Houston to continue with their professions or to start anew. But for some scientists, the task of re-engaging in their careers has been more complex. The flood waters claimed a host of data, along with valuable research materials and equipment. And for clinicians, the plummeting population of New Orleans has left them scrambling to find people who will participate in their studies (see Nature 442, 856–857; 2006 10.1038/442856a).

The anniversary of Hurricane Katrina serves as a sad reminder of the need for foresight in order to deal with unexpected disasters. One reader affected by the flooding asked for advice on how to handle the burdens of a busy assistant professorship, rebuilding his research and lab, and the desire to help his colleagues, students and family members cope with the aftermath. Our 'Ask an Expert' columnist advises that researchers deal with the tragedy much like any victim: make sure that you are coping properly before you start helping others; share your frustrations with fellow disaster victims; and regain control by finding a new routine, setting project milestones and adjusting your career timeline.

Relatively few researchers need worry about hurricanes. But changes in your personal life — the birth of a child, for example, or even an sudden illness — can also have an unexpected effect on your career (see page 240). For scientists who have coped with disasters such as Hurricane Katrina, the events serve as a reminder to make contingency plans. It's better to back up data before you lose them and to build some redundancies into experiments before your work is lost in an unforeseen incident. But the personal sphere should also be examined. What would you do if you needed to take a long leave? How would you cope if you unexpectedly lost a research partner or a job? Although no one knows when their life may change suddenly, you can anticipate that it might: hope for the best, and plan for the worst.