Not during descent --- it got to the point of doing the second burn, but that sputtered out early because the stage was spinning too fast, and the spin was centrifuging fuel to the edges of the tanks. They haven't actually said that it hit the water too hard to stay in one piece, but that's the (fairly clear) implication.
The spin was due to "aerodynamic torque" (i.e., it was spun up by the atmosphere going down), per Elon's twitter stream.
Intact as in it broke up during descent?