I'm writing a horror short-story, and at the end the main character dies and his partner is whisked away forever. I had intended to write it in first-person, because the narrative becomes more personal that way and you can really get into the head of the main character. This answer asserts that a first-person narrator has to survive to tell the tale. I know of only one way around this, which is a journal that ends right before the main character's death (The Haunter in Darkness, The Strange Case of Dr. Jekyll and Mr. Hyde), but in my story his death is only half of what makes the ending interesting so that won't work.
I had already intended to switch the POV for the last paragraph and write it in third person, so the reader can watch what happens to the two men. But does the sequence I'm going for constrain the whole story to third person?