Mildewed piano

[Ted Simmons]

     I received a phone call yesterday from a music teacher at one of the
local middle schools.  She said that one of her pianos has mildewed
internally. There was some construction work going on in the room where the
piano is located and there was a period of time when one side of the room
was open to the outside weather and it gets very humid here this time of
year. It did not rain on the piano.  I haven't seen this piano yet.  I
explained to her that in all likelihood, if the piano received that much
moisture, the strings will probably start rusting and the action will
become sluggish.  I told her it might be an insurance problem.  I'm hard
pressed to imagine such a situation.  I've never seen mildew inside a piano
and I live on the Florida coast.  I doubt that there is a de-humidifier
system in it -- she said it's moved around a lot.  I've scheduled next
Wednesday (7/17) to inspect it.  Any helpful suggestions on what else might
happen to this piano other than what I've already mentioned?  The piano is
a Yamaha studio. Any comment will be welcome.
     Ted Simmons