ugh, sorry to hear about your tub!
i have no idea about fuses, but i would flip your breakers off and look around for any surge reset switches, glass fuses, burned/brown components.
have you tried cutting th power to the spa for a few minutes and then powering it back up?
again, these are just suggestions from a electronics dabbler (not a pro)
anyone else please chime in, and in the future, should you flip the breakers off during a bad storm if you are home???