"I don't think so," she stated.
"I don't think..." her voice trailed off.
Is this second sentence correct from punctuation point of view (ellipsis working along with the same rule as
! - replacing the comma), or does it require an extra comma? (or yet something different?)
I'm aware it is normally used instead of a comma or a full stop, with very rare exceptions, but the rules of using punctuation at the end of interrupted quotes still baffle me.