Officials say “Day Zero” is imminent in Mexico City. A walk through the city reveals the historical roots of the water crisis, its present-day challenges, and the potential solutions. This episode was produced by Jesse Alejandro Cottrell, edited by Matt Collette, fact-checked by Laura Bullard with help from Anouck Dussaud, engineered by Patrick Boyd, and hosted by Sean Rameswaram. Transcript at vox.com/todayexplained Support Today, Explained by making a financial contribution to Vox! vox.com/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices