Chaos. For the first time, the Death Star is rocked by explosions as
the Rebel fleet, no longer backed against a wall, zooms over, unloading
a heavy barrage. Imperial troops run in all directions, confused and
desperate to escape. 

In the midst of this uproar, Luke is trying to carry the enormous
deadweight of his father’s weakening body toward an Imperial shuttle.
Finally, Luke collapses from the strain. 

(ROTJ Script – Completion Date December 1, 1981)