In the teeming city of Port-au-Prince, Haiti, millions of people have no reliable water supply.
Many of the underground pipes that did exist were ruptured by the 2010 earthquake. Many public water kiosks are dry.
So life for most people is a constant struggle for water. And now that cholera has invaded Haiti, safe drinking water has become Haiti's most urgent public health problem. Contaminated water is the main cause of cholera, which has sickened 530,000 Haitians since late 2010 and killed more than 7,000.
In Port-au-Prince, street vendors sell water in plastic baggies for a few pennies. Much of the city's water supply is trucked in by commercial vendors or a dwindling number of nongovernmental organizations that took on the task after the quake.
On one busy street corner, just outside one of the city's biggest slums, people with plastic buckets jostle to get to a length of garden hose that snakes out of a hole in the pavement — a source of free water.