Water, water, everywhere! Why can't billions of folks get a drink or flush a toilet?

In La Paz, a low-income neighborhood on the outskirts of Santa Marta, Colombia, water service from the local utility can be erratic or nonexistent. Pictured: Neighborhood kids stand next to a rain barrel positioned under a corrugated roof to collect water for household use.

A report from the World Health Organization says 1 in 4 people lack access to safe water to drink. Even more don't have water for sanitation. We asked someone who grew up that way to share childhood memories.

(Image credit: Ben de la Cruz/NPR)