When a toilet is flushed in Gaza City, the waste sloshes straight into the Mediterranean sea. A yearlong standoff between Israel and Hamas has left the territory's sewage system in a state of collapse, flooding its postcard-pretty coastline with human waste at the start of summer's swimming season and sending a fierce stench wafting over this crowded refugee camp and other nearby neighborhoods. The sewage problems could have potentially deadly consequences: Last year, five people were killed when a small waste reservoir collapsed. Health officials say other reservoirs are endangered, too, and the health threat from raw sewage could become deadly serious unless the situation is addressed soon; the World Health Organization already has warned people not to enter the sea. "If the amount of sewage dumped into the sea remains at this rate, we'll be facing a dark future for sea water in Gaza," said WHO official Mahmoud Daher.