In Davis v. United Services Auto. Assn. (1990) 223 Cal. App. 3d 1322, the court distinguished (1) "naturally occurring, difficult to predict earth movement" from (2) earth movement due to contractor negligence. (Davis v. United Services Auto. Assn., supra, 223 Cal. App. 3d at p. 1330.) It assumed the broadly written exclusion 4 applied only to the first risk. (Id. at pp. 1328, 1330) Then, it concluded USAA's refusal to insure against the first risk "did not necessarily mean" it refused to insure against the second. (Id. at p. 1330.) After all, "USAA may have determined the losses due to contractor negligence represented a relatively small risk . . . ." (Ibid.) "The all risk policy specifically excluded loss 'caused by, resulting from, contributed to or aggravated by any earth movement, including but not limited to earthquake, volcanic eruption, landslide, mudflow, earth sinking, rising or shifting, unless an ensuring covered loss occurred in which case the covered loss was covered.' The . . . policy did not expressly exclude losses due to the negligence of a third party." (Davis v. United Services Auto. Assn., supra, 223 Cal. App. 3d at p. 1325.)