Md. 179, 186-87, 100 A. 83 (1917). That rule was adopted to address the “unfairness inherent in charging a plaintiff with slumbering on rights not reasonably possible to ascertain.... ” Hecht, 333 Md. at 334, 635 A.2d 394. Pursuant to the discovery rule, a “cause of action accrues when a plaintiff in fact knows or reasonably should know of the wrong.” Hecht, 333 Md. at 334, 635 A.2d 394; see O’Hara v. Kovens, 305 Md. 280, 302, 503 A.2d 1313 (1986) (stating that, under the discovery rule, limitations commences when a reasonable person is “on notice,” and has sufficient knowledge to prompt a reasonable person to “undertake an investigation which, if pursued with reasonable diligence, would have led to knowledge” of the tort); Poffenberger v. Risser, 290 Md. 631, 636, 431 A.2d 677 (1981) (<HOLDING>). The effect of the discovery rule is that it
holding that a cause of action accrues when the claimant knew or reasonably should have known of the wrong recognizing that a cause of action accrues when a reasonably diligent plaintiff ascertains the nature and cause of his injury holding that a federal cause of action accrues when the plaintiff is aware or should be aware of the existence of and source of the injury not when the potential claimant knows or should know that the injury constitutes a legal wrong recognizing that under the discovery rule a cause of action accrues thereby triggering the limitations period when the patient discovers or should have discovered that he or she has a cause of action holding that in an environmental contamination ease a cause of action accrues  when a plaintiff knows or reasonably should know of his or her cause of action and of the identity of a party or parties who may be responsible for the injury