Entire east/southeast bowl of Grandview Peak slid. Slide went nearly full path, but not quite down to the flats of City Creek Meadows. Viewed avalanche from the summit of Lookout Peak around 1030am. There was a smaller natural avalanche on an adjacent bowl. This slide occurred during the last storm cycle. I observed multiple helicopters in the area. On the slope two bowls south of the avalanche, there was black residue from an explosive likely thrown from one of the heliocopters. I suspect that the large avalanche was caused by an explosive, since there was no new snow on the avalanche debris and there was a nearby slope that had been controlled with explosives. The Louis Meadows snotel in lower City Creek Canyon reported 2" of SWE accumulation Tuesday night into Wednesday morning.