In the darkness of the sewer, Barrios could see nothing. He doesn't bother to carry a light, because it would be of no use in the thick waters. He inched forward in his bright red suit, an airtight model that sealed away the disease all around him, feeling his way with his rubber gloves, listening in the darkness. He could hear the powerful, whirring pump that pushed the flow through a six-foot-wide pipe. His mission was to clear away the debris around it so it wouldn't back up into city streets. Thousands of homes have been flooded in the past by dammed-up wastewater.

"I've got it!" Barrios said as he pushed away bottles, plastic bags and other junk he could not identify by touch. At least there were no human bodies today, like the two he found floating by recently.