Down in Flames (#90)

1969-00Known Space: About Non-Fictionfanzine, Trumpet, No. 10, 1969 [not #9 as reported elsewhere], Alex Eisenstein and Tom Reamy, eds.

reprinted at;
Read It!
Destruction of Known Space, inspired by a conversation with Norman Spinrad. Never written beyond the outline phase
Niven started writing Ringworld shortly after instead. Though this saw print in 1969, it appears much further down the list in Niven's published bibliographies.

An unused outline featuring the total destruction of Known Space. Fortunately, Larry wrote Ringworld instead.