Scott Davis, Plaintiff-Cross-Appellee, Cross-Appellant v. United States of America, Defendant-Cross-Appellant, Cross-Appellee

POSNER, Circuit Judge.

Scott Davis was injured in September 1978 while diving into Devil’s Kitchen Lake in the Crab Orchard National Wildlife Refuge. The Refuge is owned and operated by the United States, and is heavily patronized — it had one and a half million visitors in 1978 — especially by students at the nearby campus of Southern Illinois University (SIU). In the nine years preceding the accident there had been five diving accidents at another lake in the Refuge, Crab Orchard Lake. One of the accidents had been fatal; two others had rendered their victims quadriplegics. Knowing there was…