The 1st sentence is in the Past perfect and the 2nd in Past simple.Difference between these two tenses is of the time frame.
When you narrate, in the present, an event that happened somewhere before i.e. in the past, you would use Past Simple. Whereas, Past perfect is used when you talk about an event that was completed before some specific point in the past.
For a better understanding of the diff between the two, you can visit here:
In your question,
the first one implies that you wish that an earthquake which happened somewhere in the past, the effects of which have settled, had not happened. There is some point of time between the happening of earthquake and your narrating of the event.
Use of Did Not implies that you are talking about a recent event.
Both of the sentences are grammatically correct. Which tense you choose would depend on the context and the time frame in which the main events are set in. There is no distinction when the sentences are taken out of context in the way it is done in this question.
For further clarification, read the answer to this similar question:
What is the difference between Past simple and Past perfect