Letters and notes, among collectors, are called ephemera. They are passing things some keep, as little external memories of friends and events. In a robbery or fire, these are the things that people are often the most hurt to lose.
In the case of the recent inventory loss, these are the things that haven't been restored yet, if they even can be.
There is a lesson we can take from this, however, and I encourage everyone to copy and paste those little scraps of text you love and save them to your local machine. I would also encourage you all to back up your local machine and keep an off-site copy.
In the digital age, Ephemera doesn't have to be ephemeral.