Recently, an avalanche called the Castle Peak avalanche ai California, USA's
Lake Tahoe area took the lives of nine people. Four were guides. What is reported in the news is that even though the slope where the victims were struck was 25 degrees, and considered too shallow for an avalanche, the slope steepend by 10 degrees more, higher up. That is where the release happened. A survivor who has chosen to relate the experiece said the warning came with a human shout, not an earthly rumble. It moved fast and was unrelenting. Finally, when trying to dig vicrims out, mainly by hand, the comment was that the snow was packed like cement, not like powder.
Something to ponder.