Updated

What was supposed to be a thrilling ride down a ski slope inside a giant inflatable ball has ended in tragedy for the two Russian men inside.

One died and the other was badly injured when the transparent plastic ball — called a zorb — veered off course and sailed over a precipice in the rugged Caucasus Mountains of southern Russia.

The men's terrifying ride — captured on video — prompted the head of the national emergency rescue services Wednesday to demand on that Russia address its lax enforcement of safety rules for winter sports, citing a series of accidents over the January holidays.

The sport of zorbing originated in the 1990s in New Zealand and is now done around the world.