The law firm of Gordon, Thomas, Honeywell, Malanca, Peterson & O'Hern (Gordon), E.M. Murray, a corporation, E.M. Murray, individually (Murray), and the Puget Sound National Bank (Puget Sound) appeal a summary judgment order of the Pierce County Superior Court dismissing the State of Washington as defendant from a suit brought by Heidi Hibbard and the estate of Robert and Maxine Hibbard against the State and all of the appellants. We reverse.
On December 6, 1977, Larry Knox unlawfully entered the home of Robert and Maxine Hibbard and proceeded to murder the Hibbards. He also allegedly raped their daughter, Heidi, on the same occasion, although the record is not clear as to whether or not he was ultimately charged with rape. Knox pleaded guilty to murdering the Hibbards and was sentenced to prison.
At the time Knox committed the murders, he was under the jurisdiction of the State of Washington, having previously been placed on probation for burglary. In addition, Knox had formerly been a patient at Western State Hospital. He obtained his release from that facility approximately 7 months before the murders and the alleged rape.
Puget Sound was appointed as the personal representative of the Hibbards' estate. E.M. Murray, then a member of the Gordon firm, served as attorney for Puget Sound in its capacity as personal representative. The probate of the estate was completed in March 1980. During the pendency of the probate, Puget Sound did not commence an action against the State on the estate's behalf or on behalf of Heidi Hibbard.
*255In 1983, the Hibbard estate was reopened and Heidi Hibbard was appointed as administratrix of the estate. In November 1983, Hibbard filed a claim with the State of Washington for personal injuries she allegedly sustained as a result of being raped by Knox. Two months later, in her capacity as personal representative of her parents' estate, she filed a claim with the State for damages for her parents' wrongful death. Both claims were denied by the State.
On February 3, 1984, Hibbard commenced an action, on her own behalf and on behalf of the estate, against Puget Sound, Murray, and Gordon. Hibbard claimed that those defendants knew or should have known that she and/or the estate had a cause of action against the State of Washington and that they were negligent in not commencing such an action on behalf of the estate, and in failing to inform her of her right to commence such an action on her own behalf. The State of Washington was later added as a defendant. Hibbard claimed that the State and its agents were negligent in "failing to protect the Hibbards from the dangerous and violent propensities of Larry Knox and that as a direct and proximate result of the tortious conduct of the State of Washington, Robert G. and Maxine Hibbard were killed and Heidi Hibbard was injured."
The State moved for summary judgment of dismissal. It argued that even if it had acted negligently, as alleged, the 3-year statute of limitations applicable to negligence actions had run on the claims against it. Hibbard responded to the motion by submitting her own affidavit in which she indicated that she had not discovered the State's negligence until October 1983. Pertinent portions of that affidavit are set forth as follows:
4. On December 6, 1977, Larry Knox brutally murdered my parents and.then raped me.
5. In the Fall of 1983, a friend called me and told me to read a newspaper article which generally described the Peterson [sic] decision/1 11
*2566. Until 1983, I did not know that Larry Knox was on probation for burglary.
7. At the time of the murders of my parents, I learned from police and others that Larry Knox had previously cut off his left testicle. I also learned that he had spent some time as a mental patient, but I knew nothing surrounding his admission or discharge from the mental hospital. I did not know that he had been involved in a traffic accident until I read Peterson [sic].
8. No one ever mentioned to me that I had a right to sue Larry Knox or anyone else. I don't recall anyone ever using the term "wrongful death."
9. The first time I learned that I might have had a right to recover money because of my parents' deaths was when I visited Attorney Gary Wallis in October 1983.
The trial court granted the State's motion, concluding that the cause of action against the State was barred by the 3-year statute of limitations on negligence actions. It concluded that the 3 years began to run on December 6, 1977, the date Hibbard's parents were murdered and Hibbard was allegedly raped. The trial court declined to apply the "discovery rule," which would have had the effect of tolling the running of the 3-year statute of limitations until such time as Hibbard knew or should have known of the State's negligence. Gordon, Murray, and Puget Sound appealed the court's order granting the State's motion for summary judgment.* 2
*257In reviewing a trial court's decision to grant summary judgment, this court engages in the same inquiry as the trial court. Hontz v. State, 105 Wn.2d 302, 311, 714 P.2d 1176 (1986). A motion for summary judgment should only be granted if there is no genuine issue as to any material fact and the moving party is entitled to judgment as a matter of law. CR 56(c); Hontz v. State, supra. All the evidence and inferences therefrom are to be considered in favor of the nonmoving party. Hontz, 105 Wn.2d at 311. If reasonable minds can differ as to the conclusions to be drawn from the evidence, then a motion for summary judgment should be denied. Fleming v. Stoddard Wendle Motor Co., 70 Wn.2d 465, 467, 423 P.2d 926 (1967).
The overriding issue with which we are here confronted is whether the trial court erred in concluding, as a matter of law, that the 3-year statute of limitations had run on Hib-bard and the estate's cause of action against the State of Washington. To answer this question we must examine the so-called "discovery rule" and determine whether or not it applies in this case.
Gordon, Murray, and Puget Sound argue that the discovery rule does apply. They contend that the statute of limitations on Hibbard's claims against the State was tolled until such time as she discovered or reasonably should have discovered that she had a cause of action against the State. The State responds that the discovery rule is not applicable, and argues, additionally, that even if the discovery rule is available in this type of case, it is not applicable here because Hibbard should reasonably have discovered that she and the estate had a cause of action against the State at the time her parents were murdered and she was raped.
The applicable statute of limitations in this case, by agreement of all the parties, is RCW 4.16.080. It is a 3-year *258statute under which the limitation period for a cause of action commences when the action "accrues." Ordinarily an action accrues at the time of the act or omission. White v. Johns-Manville Corp., 103 Wn.2d 344, 348, 693 P.2d 687, 49 A.L.R.4th 955 (1985). In some cases, however, the injured party does not know, or cannot know, at the time of the tortfeasor's act or omission, all the essential elements of his or her cause of action. In such cases, the cause of action accrues when the plaintiff knew, or reasonably should have known, all the essential elements of his or her cause of action. Reichelt v. Johns-Manville Corp., 107 Wn.2d 761, 769, 733 P.2d 530 (1987). This is the so-called "discovery rule."
Until now the courts of this state have only applied the discovery rule to "certain torts." Gevaart v. Metco Constr., Inc., 111 Wn.2d 499, 501, 760 P.2d 348 (1988) (quoting an unpublished opinion of Division One of this court, noted at 48 Wn. App. 1034 (1987)). For instance, the rule has been applied in products liability, wrongful death, professional malpractice, and fraud cases. See Reichelt v. Johns-Manville Corp., supra (products liability); White v. Johns-Manville Corp., supra (wrongful death); Ohler v. Tacoma Gen. Hosp., 92 Wn.2d 507, 598 P.2d 1358 (1979) (medical malpractice); Busenius v. Horan, 53 Wn. App. 662, 769 P.2d 869 (1989) (fraud).
The rationale for applying the rule in those cases was to strike a balance between the "preservation of limitations on the time in which the action may be brought and a preservation of the remedy, too, where both parties are blameless as to delay in discovery of the asserted wrong." Ruth v. Dight, 75 Wn.2d 660, 666-67, 453 P.2d 631 (1969) (first case to apply the discovery rule in this state). Taking into consideration the rationale for the rule and the fact that in any negligence case the plaintiff might not have knowledge of all the elements of his or her cause of action, we see no reason to limit the application of the rule only to certain negligence cases. We therefore hold that the discovery rule applies in all negligence cases where the plaintiff *259could only have known all the essential elements of his or her cause of action at some time after the actual occurrence of the alleged tort.
Nevertheless, we acknowledge that the plaintiff has an affirmative duty to exercise due diligence in pursuing all the elements of his or her cause of action. See North Coast Air Servs., Ltd. v. Grumman Corp., 111 Wn.2d 315, 319, 759 P.2d 405 (1988) (claimant in products liability case must have discovered, or in exercise of due diligence should have discovered, a factual causal relationship between the product and the harm); Gevaart, 111 Wn.2d at 502 (by exercise of due diligence, plaintiff could have discovered all the elements of her cause of action). The affirmative duty of due diligence imposes a burden on the plaintiff to take every available step to pursue the elements of his or her cause of action. Gevaart v. Metco Constr., Inc., supra. If due diligence is not exercised by the plaintiff in a timely manner, the cause of action will be barred by the statute of limitations. Reichelt, 107 Wn.2d at 772.
In determining whether a plaintiff has exercised due diligence, the trier of fact is to apply an objective standard and ask whether the plaintiff has exercised the diligence that a reasonable person would exercise in the same or similar circumstances. The trier of fact is to determine the point at which the plaintiff had knowledge or should have had knowledge, of each of the four elements of a cause of action. Once the plaintiff has some information about each of these four elements (i.e., duty, breach, causation, injury), the statute begins to run regardless of whether the plaintiff is aware of a legal cause of action at that time. Olson v. Siv-erling, 52 Wn. App. 221, 228, 758 P.2d 991 (1988), review denied, 111 Wn.2d 1033 (1989); Wood v. Gibbons, 38 Wn. App. 343, 685 P.2d 619, review denied, 103 Wn.2d 1009 (1984).
Having concluded that the discovery rule may be applied in any negligence case, we must now turn to the question of *260whether the trial court erred in granting summary judgment here. The State argues that there is no factual question as to when Hibbard reasonably could have known all the elements of her cause of action because she was aware of her injuries on the date of the murders and there were no hidden injuries to discover. Gordon, Murray, and Puget Sound, while conceding that Hibbard was aware that a tort had been committed by Knox on the date of the murders and alleged rape, contend that she was not aware of all elements of her cause of action, i.e., the State's negligence. Although Hibbard's affidavit reveals that she knew Knox had been a "mental patient," there is no indication that she knew before 1983 that he had been under the supervision of the State as a mental patient or as a probationer. Consequently, it cannot be said that she was aware that the State might have been negligent in supervising Knox before 1983. Viewing Hibbard's affidavit as we must, we conclude that reasonable minds could differ as to when Hibbard knew, or should have known, of the State's alleged negligence to Knox and resulting negligence to Hibbard. See Martin v. Patent Scaffolding, 37 Wn. App. 37, 44-45, 678 P.2d 362, review denied, 101 Wn.2d 1021 (1984).
In our judgment, the extent of Hibbard's knowledge is a question of fact to be answered by the trier of fact. It is up to a judge or jury to decide the point at which Hibbard knew or should have known of the State's alleged negligence, and whether or not Hibbard exercised due diligence in learning all of the elements of her cause of action in a timely manner. Gevaart v. Metco Constr., Inc., supra.
Summary judgment should not have been granted and, therefore, we reverse the order of summary judgment.
Worswick, C.J., concurs.
In Petersen v. State, 100 Wn.2d 421, 671 P.2d 230 (1983), the Supreme Court discussed the fact that a woman by the name of Cynthia Petersen was *256injured when her car was struck by a vehicle driven, coincidentally, by Larry Knox. According to the opinion, Knox ran a red light before striking Petersen's vehicle. The court pointed out in Petersen that Knox appeared to have been under the influence of drugs. The Petersen opinion also revealed that Knox was on probation for burglary and had been committed to Western State Hospital. While at Western State, Knox was treated by a Dr. Miller who was aware that Knox was on probation and that he had an extensive history of drug abuse, including the frequent use of "angel dust." The opinion disclosed that Dr. Miller released Knox from Western State 5 days before the accident, notwithstanding his knowledge of Knox's dangerous propensities and reckless behavior at the hospital on the evening before his release. Petersen, 100 Wn.2d at 423-24.
Only an aggrieved party may appeal to this court. RAP 3.1. The parties have not addressed the right of Gordon, Murray, and Puget Sound to appeal the trial court's dismissal of Heidi and the estate's cause of action against the State. The claims of Heidi and the estate against Gordon, Murray, and Puget Sound fail if the court finds that the action against the State was not time barred. Therefore, *257we can only assume that the parties agree that Gordon, Murray, and Puget Sound are aggrieved parties because their pecuniary rights are substantially affected by the trial court's dismissal of the case against the State. See Cooper v. Tacoma, 47 Wn. App. 315, 316, 734 P.2d 541 (1987).