Both are correct. The question is, which one is appropriate for this scenario.
It is correct that when you are describing two events that happened in the past, you should use past perfect for the earlier event and simple past for the later one to show or emphasize the sequence of events.
Well, the key is here. You would need this construction if the sequence of events needs to be emphasized. If it is obvious, then you can go with simple past for both the events. Unlike the brown sparrow, the passenger pigeon was slaughtered indiscriminately and became extinct in 1914.
. It is obvious that slaughtering must come before the extinction. The reverse can never happen. So in this case you can go with simple past for both the actions and can still have the clear meaning.
Look at the another example Antonio DROVE to the store and BOUGHT some ice cream.
and what about this?? Laura LOCKED the dead bolt before she LEFT for work.
has already made the sequence of actions amply clear, so you do not need past perfect to emphasize that.
Finally, I would say that the meaning of the sentence would determine which tense to go with.
Hope that helps.
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