# On what conditions is a question automatically deleted?

I posted a question titled "Construction of a $k$-variety from a separated scheme of finite type over a field $k$" in December last year. It was deleted yesterday by "Community". Here is the link to the deleted question. It had had no answer. I think it got negative reps for the first time less than a week ago. I think a question will be deleted if it has negative reps and has no answers for 30 days. So I think it was deleted too early. Am I wrong?