The disappearance and death of Norwegian biathlete Sivert Guttorm Bakken has deeply shocked the sports community. Bakken, who was found dead in his hotel room at Lavazè Pass, Italy, on December 23 while wearing an altitude mask purchased online from Spain, died following an incident linked to hypoxic training. Investigations are focused on the altitude mask, which was not supplied by the national team, and is currently undergoing technical analysis to determine if malfunction or misuse caused his death. Bakken had a known heart condition, and authorities are examining the safety of consumer-grade altitude equipment. The biathlon world mourns Bakken, with poignant accounts from Ingrid Landmark Tandrevold and Tommaso Giacomel, who was training with Bakken at the time of the tragedy. Giacomel, overwhelmed with grief, dedicated his recent victory in Oberhof to Bakken, expressing that he hopes Bakken would be proud of him. Bakken's funeral is scheduled for January 13 in Lillehammer. The community plans tributes including a minute of silence and a bib with his number during upcoming races. Bakken’s death has prompted Norwegian authorities to advise caution regarding the use of simulated altitude in sports. The incident raises questions about the safety of consumer altitude training devices and the regulation of their sale. Giacomel, visibly emotional, continues to honor his friend’s memory and has expressed hope to attend Bakken’s funeral and possibly dedicate his Olympic performance to him.