Senior station officer Ryan McCarty from Napier said the truck was held above the ravine by two large trees that snapped in the crash.
"So he was sort of hanging - the truck was wedged against one bank and the back side was overhanging the ravine. The ravine was a quite a steep drop underneath, probably a good 30m ... as far as extrications go it was probably about as hard as they come."
A rescue helicopter attended but the person was taken to hospital by road ambulance. Their condition is critical.