Which of two following sentences is correct?
Depending on whether a birth or a death occurs , we have...
Depending on whether a birth or a death occur, we have...
Update I changed the title.
Which of two following sentences is correct?
Depending on whether a birth or a death occurs , we have...
Depending on whether a birth or a death occur, we have...
Update I changed the title.
OP's example #2 looks a bit unlikely, but in certain contexts it could be valid. As they say, it all depends on the "whether" - in this case, whether the two possibilities are...
1 A: a birth occurs, OR B: a death occurs
2 A: a birth or death occurs, OR B: neither of those things happens (happen??!!!)
If OP intends the second distinction, the plural verb form in #2 is fine.
I wouldn't have a problem with a hotel manager saying...
"It all depends on whether the King or Queen turn up - if not, we might be able to let you have the Royal Suite tonight"
In that context, the two possibilities referenced by whether are that either a senior royal arrives (and thus gets the best room in the house) or neither of them do (in which case you will get the accommodation upgrade).