Just when we thought it was safe to drink the water.

Algiers residents appeared to dodge last week’s hard freeze, only to see a boil water advisory Tuesday.

Truth is, most of Louisiana was frozen out last week, not just New Orleans. The East Bank of Jefferson, for example, also had to boil water after the freeze.

Here’s the lesson: Public infrastructure across south Louisiana is more vulnerable than we ever imagined. Freezing weather from the north poses as much danger as a hurricane from the Gulf, because it can be just as deadly.

We always learn some hard lessons after a storm. Hopefully, citizens as well as government will be better prepared next time.