Millions watched on television last week as 25-year-old Caleb Moore attempted a back flip on his snowmobile during the Winter X Games, only to wind up in an ambulance after being knocked unconscious during a crash landing.

When he died Thursday morning in a Colorado hospital, the news came through simple and sad statements from his family and from ESPN, the network that created the ever-expanding X Games in 1995 as a showcase of action-packed sports.

Moore’s death appears to be the first directly related to the X Games, ESPN’s high-flying carnivals. It immediately raised cultural questions about the lure of such events to young daredevils, the appeal to viewers and the responsibility of organizers.

A generation ago, such televised feats were the domain of singular performers like Evel Knievel. But with the growth of the X Games and sponsors like Red Bull that have rushed into the death-defying stunt business, the pool of willing participants seems bottomless.