Board Thread:Naruto Discussions/@comment-3568954-20160615123337/@comment-9782468-20160617142936

@UltimaDude, he was attempting the Tailed Beast Rasengan, and he wasn't interrupted. He just failed. As Mr. Rubber noted.

Ajr1218 wrote: Kakashi didn't die from losing all his chakra, he died from reaching a low enough point where life could not be sustained. Now the desiccated corpses littered around the Shinju, on the other hand, have been completely drained of chakra.

Kakashi already said that if your chakra hits zero, you die. That's been established since part 1. He didn't say if your chakra is too low, he said if it hits zero. Yeah, Kakashi was out of chakra.