I got pretty full beta from one of the team at a memorial last night. They had crossed the river on Wednesday from south to north, to canyoneer a canyon just upstream. After rapelling and downclimbing Deer Creek, they stayed on the north side of the Kings till morning. Luca tried to tow a rope across to facilitate the other two crossing. One other team member had already tried it and they pulled him back across when he decided he would not make it. Luca made it further, but too much rope was out. (with the current dragging it downstream.) They were unable to pendulum him all the way back to shore. The rope came taught with Luca in the small rapid immediately below the confluence. Luca probably had some sort of releasable knot but was unable to free it. The others tried to get throw ropes to him to no avail. They cut the rope, but he was perhaps unconscious by then. He floated downstream till the rope snagged again and stranded him underwater.
Lot of good stories about Luca. Super enthusiastic and super helpful guy. Everybody loved and respected him.