Mezue ahịrịokwu na-esonụ: A tụlere ọtụtụ n'ime ajụjụ ndị a ọzọ na 1986 na-esote nchọpụta nke nnukwu ọdịda yiri nke ahụ nke Bureau of Reclamation's Teton Dam na June 1976, na ihe fọrọ nke nta ka ọ bụrụ ọdịda nke Ngalaba Mmiri na Ike nke Ngalaba Lower Van Norman Dam na
Ala ọma jijiji mere na San Fernando n'afọ 1971. Prọfesọ Ronald Scott nke Caltech, onye sonyere na ọmụmụ Casagrande, kwuru na ogbako na-esochi 1987 na Baldwin Hills na Casagrande elegharala anya ma ọ bụ amaghị maka mmegharị ala nke doro anya na ọ nweghị ihe jikọrọ ya na ọdọ mmiri (dịka ndị dị na Stocker-LaBrea) na nyocha ya. Onye injinia ọzọ, Stanley Wilson - onye rụkwara ọrụ na Casagrande na nyocha nke 1972 ma kwado nkwupụta ahụ bụ na ọdịda mmanụ mmanụ bụ ihe na-adịghị mkpa - ugbu a kwetara na mbugharị ala yiri nke ahụ gbatịrị nke ọma na mpụga ebe nchekwa ahụ, ọkachasị na mpaghara Stocker-LaBrea, nke mere na enweghị ike ịkọwa ebe nchekwa ahụ na mmejọ ndị ọzọ na ebe nchekwa ahụ n'onwe ya - si otú a na-ekwu na ọ bụ ọrụ mmanụ mmanụ kpatara ọdịda ahụ. N'ihi ya, echiche ndị e nwere banyere otú ebe a na-egwu mmanụ si adaba na otú e si eme ka mmiri ghara ịba n'ime ala yiri ka hà kwekọrọ.