Well, I hope the police are taking this very seriously. I had my hangar burned down in 1970 by a nutter who just had to have a fire on the anniversary of the day when his wife had bogged off and left him.
He actually had absolutely nothing to do with the club or any of the members or even aviation in general.
We lost all of our aircraft and eight years of hard graft that night. Luckily we were properly insured but it hurt like hell and no amount of money was ever able to put back what we lost.