I've been through this (see photo) -- forget homeowners insurance if you play out. And even if you don't, it may be a hassle and you may need to check your policy limits, which set dollar caps on certain categories, like jewelry.
That's my pair of 18" folded horn cabs on the left, grille cloth burnt, insides roasted, the Peavey head on top with the plastic front melted. Blackface Fender Bassman head (used for monitors) on the floor in 3" of water. It wasn't a pretty sight. Ten feet away the whole roof had caved in. We scraped melted tolex off cabinets, sanded and recovered them with new speakers inside. It was very depressing and very expensive. I hope it never happens to you.
Musical instrument insurance is a good investment. The photo above is from around 1975- we played a club Friday night, came back to do Saturday and found it mostly burned to the ground. No help from the owner- the bastard never even called us to tell us it burned down early that morning and never even paid us for the Friday performance. We were only a week or so from getting group insurance; got a policy app through the Musicians' Union and were waiting for the ******* guitarist to get his receipts together.
I should mention my van was broken into in '81 and a few things were stolen, including my Polytone bass amp. That time I had insurance.
I have my musical instrument insurance through Merz-Huber -- they and another company offer roughly the same rates. There is a link to both companies under MISC on my Double Bass Links page at
http://www.gollihur.com/kkbass/basslink.html
If you just call out of the blue, the rates will be high. The trick is to belong to a qualifying organization. For instance, I belong to the ISB (International Society of Bassists), a Double Bass organization, which is $35/yr. for membership; you get newsletters and magazines - big deal. However, by being a member you get a rate less than half regular folks get. You can usually ask these outfits what club you might have to join - who cares if it's not bass-related if the savings is five times the dues?
I insure over $20K worth of stuff (basses, amps, effects, rack cases) for a little over $110/yr. All risk, whether you leave a bass on the loading dock or a drunk knocks over your stack, $100 deductible.
Pardon the long message, but I hope you assess your own risks and do something rather than wish you had. I don't feel bad about leaving my stuff overnight at clubs.