Hi - We have a two year old ProForm Tempest (Costco special

). We went out to check temp this morning and the tub was off. Checked the outside breaker and it was tripped and won't reset.

The breaker in the main house panel was not tripped.
We had a pretty wicked storm roll through Thursday night, but nothing else in the house was affected and no power outage or brownout. It would seem a power strike or surge would affect the main panel before the external one, but I'm no pro electrician. Plan is to replace the exterior GFI 50a breaker tomorrow.
Any other suggestions?? Any thought about the tub itself? Think it took a hit, or did the breaker do it's job??
TIA
-PGT