His last moments were described early today by Father Jarek Cielecki, director of Vatican Service News, a Catholic TV channel. "The Holy Father died looking towards the window as he prayed, and that shows that in some way he was conscious," Cielecki said.
"A short while before dying, the Pope raised his right hand in a clear, although simply hinted at, gesture of blessing, as if he became aware of the crowd of faithful present in St Peter's Square, who in those moments were following the reciting of the Rosary," he added.
"Just after the prayer ended, the Pope made a huge effort and pronounced the word 'Amen'. A moment later, he died."
(A bit more on his final word here.)