The Crans-Montana fire: a Swiss tragedy that raises questions
Around 40 people were killed and over 100 others injured in the blaze at the New Year's party.
As investigators begin the gruelling task of identifying the victims and trying to determine what happened, here are some of the main issues they will seek to probe.
How did the tragedy occur?
"It was around 1:30 am (0030 GMT) when smoke was spotted" coming out of Le Constellation bar at the heart of the upscale resort, police commander Frederic Gisler told reporters.
A few seconds later, a witness contacted the police.