The San Francisco Suicide Club was an idea conceived by the late Gary Warne, and existed from 1977 to 1982 in San Francisco.
You are cordially invited to read about it here on Wikipedia:
What follows is the original historical material as originally presented in 1977:
THE SAN FRANCISCO SUICIDE CLUB
Have you ever explored a subterranean sewer at night with forty other people; climbed three stories on a swinging rope ladder to dine on the roof of a condemned building; staged practical jokes you’ve always fantasized about?
No…? How about infiltrating a cult or talking a policeman into hitting you with a pie? Well… we hadn’t either.
The surviving members of the S.F. SUICIDE CLUB have agreed to EXPERIENCE THINGS THEY HAVEN’T EXPERIENCED BEFORE. In most cases they are challenges that we wouldn’t or couldn’t do alone because of the danger or need for team work. A large group also provides more investigators into the unknown, as uncovering mystery and adventure in the 20th Century requires a lot more detective work. Events generally fall into three categories: Adventures, infiltrations, and stunts. As you may notice in the above emphasized phrase, no WHY or PHILOSOPHY is attached…