This 11-year-old girl is "America's Top Young Scientist" with her invention of Tethys, a device that detects lead in water.
Gitanjali Rao was affected by the Flint, Michigan water catastrophe when the city started using the Flint River for water in 2014, sparking a crisis that was linked to an outbreak of Legionnaires' disease, at least 12 deaths and dangerously high lead levels in children.
The seventh-grader said it took her five months to make Tethys from start to finish. Rao won the 2017 Discovery Education 3M Young Scientist Challenge, along with a $25,000 prize.