KJV:
And forthwith Jesus gave them leave. And the unclean spirits went out, and entered into the swine: and the herd ran violently down a steep place into the sea, (they were about two thousand;) and were choked in the sea.
NASB:
Jesus gave them permission. And coming out, the unclean spirits entered the swine; and the herd rushed down the steep bank into the sea, about two thousand of them; and they were drowned in the sea.