Rear wheel locked at 40 mph and power cutoff while on a highway on ramp (soft right turn) making the rear wheel slide to the right, causing my passenger and I to fall off the bike hurting our left extremities (legs, arms, wrists, elbows, shoulders) as it slid and ended on its left side on the right shoulder. Harley-Davidson RDRS and Rain Mode were turned on and the road was wet from a previous rain but visible debris on the road.