I had to call my local fire department when I had a similar issue.
I told them I'd placed it in a parking lot away from anything flammable, and they said they "couldn't advise me" -- I got the sense they were either being passive aggressive, or were encountering new issues similar to the lessons that had to be learned the hard way when lithium batteries became ubiquitous, then enlarged and put into cars.
(In that case, you don't put water on the fire, you have to use chemicals)
It's scary when folks withhold labor in contexts that you really shouldn't but that's why I put in to renew my US passport early -- if folks are unwelcoming, there's plenty of more sane places to live...
The internet is global, but in the American system I've lived in all my life of volunteer fire services, paired with militant libertarianism paired with militiaesque "Don't volunteer for anything" admonishments best reserved for actual soldiers sets the world ablaze, metaphorically.