What does 'go down with' mean here?
http://www.rd.com/true-stories/love/widow-rafting-husbands-ashes/
What was I doing down there? My sister Kathryn, who had seen me through his death, loves the Grand Canyon, and she arranged the trip.
She said, “Come on, Neshama. It’s the trip of a lifetime. You weren’t able to go down with John, because it was too far from medical help [for him]. So come.”
-- from www.rd.com