The 24-year-old actress says it “felt like losing a limb.”
“That was one of the most difficult things that any of us ever had to film,” Willa told the crowd during MCM Comic Con. “This was four years in, so we were all so close at this point.”
Of course, there is potential for Katie to come back.
She’s already appeared on The Flash as Earth-Two’s Black Siren.
“It’s not like she’s gone,” Willa added.