KJV:
And it came to pass, when he made mention of the ark of God, that he fell from off the seat backward by the side of the gate, and his neck brake, and he died: for he was an old man, and heavy. And he had judged Israel forty years.
NASB:
When he mentioned the ark of God, Eli fell off the seat backward beside the gate, and his neck was broken and he died, for he was old and heavy. Thus he judged Israel forty years.