Minnesota Clip

"In the US, this is called a "Minnesota Clip" due to an unfortunate
accident on El Capitan. Minnesota is a state not known for its
climbing resources. Two climbers from Minnesota were climbing The
Nose on El Cap in Yosemite in the 1970's. They came to an anchor at
a hanging belay, two bolts with a chain between. They clipped their
carabiners OVER the chain, and did not clip into either bolt or INTO
the chain. Their weight caused one bolt to fail, and they slid off
the end of the chain and took the big ride."

Quoted from Tom Jones in an email to the OzCanyons yahoo group