You can check out the behind-the-scenes footage in the embed, which reveals one of Cassian and K-2SO’s many fates.
This expose on the VFX seen in Rogue One delves into the creation of Imperial droid turned rebel K-2SO.
That said, the rest of us who have seen the movie know that all of the main characters in Rogue One: A Star Wars Story meet there demise in the third act.
We also know that Cassian suffers a deadly fall helping Jyn get the plans out of the Imperial base they’ve infiltrated on Scarif.