After a crisis, how can we tell if water is safe to drink? Current tests are slow and complex, and the delay can be deadly, as in the cholera outbreak after Haiti's earthquake in 2010. TED Fellow Sonaar Luthra previews his design for a simple tool that quickly tests water for safety -- the Water Canary.

TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes.