Got to this website to get aerial shots of the Island to assess roof damage (at least as close as you can get). Also George Hannie sent this link as well.
Here’s George’s (which may be the same, haven’t checked):
Also, for GHF: they are operating out of Preservation Texas in Austin.
Check National Trust for Historic Preservation for updates on historic landmarks, structures, etc. and to send folks interested in volunteering once big clean-up happens, they can sign up on the this site.