The nose in the tent is that they didn't say it's full of water, they said it's full of [something I've never heard of], and presented in a newsy-alarming way, in venue where people are accustomed to getting snippets of news while they're doing something else. "Traffic on the freeway, be careful." "It's cold today, dress warm." "Something you've never heard of in the water, take precautions."

Suspension and disavowal probably went too far. A corporate and DJ apology would have been enough.

It was something facetious and intended as an "is your refrigerator running"-style prank. I am sure that most recipients of that call did in fact have refrigerators that were running, too. As a waste of government resources, such pranks are a problem. That line is intended as an emergency number. Chemical spills and biological contamination in water supplies is not a joke. These people just thought they were being clever.