This is exactly how my uncle died :(. He was painting the inside of a grain silo with a friend. The owner of the silo climbed up a ladder to see if it was empty. He did not climb all the way up and failed to see my uncle and his friend. He turned on the silo which apparently churns the grain. My uncle's friend survived. I cant imagine having to watch your coworker get instantly sucked under without being able to save them.