I'm sorry I missed the festivities.
It was due to the high-current welder.
The welder is used at the shop often, with no problems. But it could have been the last straw for a failing transformer.
Did they have to replace the transformer? Or was it just a transformer fuse?
What usually happens is that a squirrel will step from the energized line to the (grounded) transformer case, and blow the fuse. (Which also blows the squirrel into next week.) The fuse is about the size of a slightly short, fat paper towel tube.
Power company people call squirrels "pole rats". If you look around, you may find the little sumbeetch laying at the bottom of the pole.
