In Dallas County Mental Health & Mental Retardation v. Bossley, 968 S.W.2d 339, 343-44 (Tex. 1998), the plaintiffs' son R was committed to a Dallas County Department of Mental Health and Mental Retardation ("MHMR") facility after a failed suicide attempt. He surprised an MHMR technician unlocking an exterior door to go to lunch, "pushed her aside, and fled." Bossley, 968 S.W.2d at 340-41. He went to an interstate about one-half mile from the MHMR facility and attempted to hitchhike a ride. As MHMR personnel and police approached him on the roadside, "he leaped into the path of a truck and was killed." Bossley, 968 S.W.2d at 341. The plaintiffs alleged both a use of property--the technician's unlocking of the outer door--and a condition of property--an unlocked inner door--as causative events which waived Dallas County MHMR's immunity Bossley, 968 S.W.2d at 343. The Court examined the geographic, temporal, and causal proximity of the use and condition alleged and determined that they "were too attenuated from R's death to be said to have caused it." Id. The Court concluded: The real substance of plaintiffs' complaint is that R's death was caused, not by the condition or use of property, but by the failure of Hillside's staff to restrain him once they learned he was still suicidal. the Tort Claims Act does not waive Dallas County MHMR's immunity from such a complaint. Id.