Schools are required to complete a certain number of fire drills each year. Not long ago,  one more fire drill had yet to be completed for the school year. Summer repairs had already begun in our school building  and as a result the bell system was not quite  working .  The principal decided that
for the day's drill, an announcement would be made over the intercom.

The weather was delightful and so my second graders completed  a number of their science activities outdoors. They practiced  changing  the physical states of water.  We returned to our the classroom and began to write up
our experiments.  The noise level in the classroom was high as students happily shared their findings with one another.  Not surprising, it was
rather difficult to make out words of the fire drill announcement.

As I fetched the classroom keys and student  roster for our departure,
several children ran over to my desk and shared in the gravest of tones  

"She said we have to evaporate the building."