1. If they failed to light the lanterns, they were fined heavily.

Question

2. If they failed to light the lanterns, they would be fined heavily.

(Would you explain the difference between #1 and #2? Thank you. Have a good time.)

Answer 1

1 is stating a fact.

I think 2 is supposed to be factual, too, but the use of "would" is not quite correct, since that's an auxiliary verb that should be used for possibilities, not facts.