Toledo works to restore trust in its water supply
Four years ago, the city of Toledo told more than 450,000 residents to immediately stop drinking water out of the tap.
That's after a toxin called microcystin was detected in the water. The toxin came from a bloom of cyanobacteria that had surrounded the city's water intake in Lake Erie.
The incident caused panic among some residents, hoarding of water, even fights at bottled water distribution sites - along with a lot of unwanted national media attention.
And it taught the city some hard lessons.
What happens to the water Toledo takes from Lake Erie
Municipal water treatment is a painstaking and complicated process.