from another source:
Fernand Petzl, inventor of the famous Petzl gear that
is so well known to cavers and climbers, died
yesterday, Saturday May 31, after a lengthy illness,
at the age of 91.
In 1942, Fernand Petzl began testing the first nylon
ropes. He also started manufacturing cable ladders for
caving. A passionate caver himself, he participated in
much exploration, namely in the Gouffre Berger
(France) which became the world's deepest cave in
1956, with a depth of 1122 meters (3680 feet). He
continued inventing prototypes of caving equipment in
his small workshop in France, and fine-tuning the gear
by taking advice from his caving friends. He founded
the Petzl company in the mid-70s.