User blog comment:1967 impala/who is death SPOILER!!!!/@comment-1159766-20151116150929

Okay so I don't think anything happens to Thea not only because Speedy is an important part of the Green Arrow lore (which they seem to finally be going back to) as Mia Dearden but also as Emiko Queen. The child they said they weren't going to be going into any time soon.

My guess is it is Felicity, not only did she mean something to Oliver and Barry, but if my own theory is correct, Damien Darhk is her father and he kills her to prove to Oliver he means business and Oliver would turn back to being a killer (GA was more of a killer in the comics) plus it would make the show lean more toward the comic book role anyway if Felicity dies.