Prosecutor: Fatal Italy avalanche likely unpredictable event

Hikers walk past the Marmolada mountain and the Punta Rocca glacier near Canazei, in the Italian Alps in northern Italy (Luca Bruno/AP)

Authorities said conditions in the Italian Alps are too unstable for search teams and dogs to work on the mountain where five people remained missing after a fatal weekend avalanche.

Seven people were killed after an enormous chunk of a glacier broke off on Sunday, sending an avalanche of ice and rocks thundering across a trail where hikers were enjoying warm, sunny weather.