According to Job 1:16, what fell from heaven and burned up Job's sheep and servants?

Answer: The fire of God

A messenger reported, "The fire of God fell from heaven. It burned and consumed the sheep and the servants." (Job 1:16)

“While he was still speaking, another messenger came and reported: “The fire of God fell from heaven. It burned and consumed the sheep and the servants, and I alone have escaped to tell you!””— Job 1:16 (BSB)