Makerbot z18 extreme stringing of walls

From the look of the print, it looks like it was oriented with the wall you're pointing at at the top, facing down? If so, that's a really long bridge and I'm not surprised it's drooping. Can you rotate your print 90 degrees and reorient it so it prints in the orientation you've photographed it? I can't see the rest of the piece from your photo, but from what I can see it should print OK that way an you won't get the drooping.