Appellants, Gary and Cheryl Nuspl, appeal the dismissal of their suit for contract reformation, breach of contract, and negligence. The Circuit Court of the City of St. Louis dismissed appellants’ suit against both respondents, Missouri Medical Insurance Company (“Momedico”) and Rollins Burdick & Hunter (“RBH”), on statute of limitations grounds. We affirm in part and reverse in part.
On November 25, 1972, appellants’ son, Keith Nuspl,1 was born. As a result of alleged medical malpractice, Keith sustained serious injuries which, appellants claim, eventually resulted in his death on February 20, 1990. Appellants filed suit against Dr. Hugh Smith, the obstetrician who delivered Keith, on July 11, 1985, and Dr. Smith was served on December 5,1985.
Until 1979, Dr. Smith was covered by a “claims made” medical malpractice policy, which he purchased from Lloyd’s of London. A policy of this type covers only those claims made while the policy is in force. In 1979, however, Dr. Smith changed his malpractice coverage to an “occurrence” type policy, which he purchased from respondent Momedico. This type of policy covers the policy holder for all events which occur while the policy is in effect, regardless of when the claims for those events are made. Momedico’s policy contained a limited prior acts endorsement, which provided Dr. Smith with coverage for acts committed between December 1, 1976, and the date of the policy’s inception in 1979. These circumstances left a gap period in Dr. Smith’s malpractice coverage for any potential claims occurring prior to December 1, 1976, which had not yet been filed. Appellants’ suit, which arose from acts occurring on November 25, 1972, and had not been filed until July 11, 1985, fell within that gap.
On January 8, 1991, appellants and Dr. Smith entered into a consent judgment for one million dollars. In addition, Dr. Smith assigned all causes of action against his insurance carriers to appellants. In return, appellants agreed not to levy execution on any property owned by Dr. Smith. Appellants filed the instant suit against Momedi-co that same day, claiming Dr. Smith’s policy should have provided coverage all the way back to 1972, as he allegedly requested. On May 29, 1991, appellants amended their suit to name RBH, Dr. Smith’s insurance agent in the above transaction, as an additional defendant, alleging RBH failed to request adequate coverage for Dr. Smith. Both Momedico and RBH moved for judgment on the pleadings, based on the statute of limitations. After oral argument and submission of written memoranda, the court sustained respondents’ motions on January 23, 1992. On January 30, the court entered a supplemental order clarifying the January 23 order. Appellants appeal the court’s entry of judgment on the pleadings.
For their only point on appeal, appellants claim their causes of action were not barred by the applicable statute of limitations. We partially agree.
In reviewing a judgment granted on the pleadings, we consider only such facts as were well pleaded in appellants’ petition below. Tomlinson v. Kansas City, 391 S.W.2d 850, 852-53 (Mo.1965). Respondents do not claim insufficiency of the pleadings to state a cause of action; respondents’ only contention is that the actions are time-barred.
BREACH OF
CONTRACT/NEGLIGENCE CLAIMS
All parties agree the applicable statute of limitations for negligence claims is five years. RSMo § 516.120 (1986). There is, however, some dispute regarding breach of contract claims. Appellants averred in their petition that, because the claims were based on the written insurance policy, and *922not an oral contract, the applicable statute of limitations is ten years. RSMo § 516.-110 (1986). We do not address this issue because the trial court made no finding on this subject, therefore the question is not properly before us.
Respondents’ contend the causes of action accrued, and the limitations period began to run, either (a) when the policies were first delivered in 1979, or (b) when suit was filed against Dr. Smith on July 11, 1985. For respondents to prevail, one of the above contentions must be correct as a matter of law. We conclude respondents are incorrect.
RSMo § 516.100 (1986) provides, in relevant part:
[T]he cause of action shall not be deemed to accrue when the wrong is done or the technical breach of contract or duty occurs, but when the damage resulting therefrom is sustained and is capable of ascertainment ...
As respondents point out, the phrase “capable of ascertainment” refers to the fact of damage, not the precise amount of damage. Earls v. King, 785 S.W.2d 741, 744 (Mo. App., S.D.1990). We note, however, that the mere occurrence of an injury may not necessarily coincide with the accrual of a cause of action.
This court recently decided a very similar case in Community Title v. Safeco Ins. Co., 795 S.W.2d 453 (Mo.App., E.D. 1990). An owner of a building directed an insurance agent to procure the necessary fire coverage, and the building was subsequently destroyed by fire. Allegedly due to the agent's negligence, the coverage was not as requested, and was quite insufficient. The agent moved for summary judgment on statute of limitations grounds, claiming, as here, the limitations period began to run when the policies were delivered. Id. at 458. Reversing the trial court’s grant of summary judgment in favor of respondent’s agent, this court stated:
[At] the time the policies were delivered, appellants had no claim against [respondent] because none of the risks appellants sought to insure against had occurred ...
Community Title, 795 S.W.2d at 459. Here, quite obviously, none of the malpractice litigation had occurred by 1979, and Dr. Smith had no inkling his personal assets were at stake when the suit was initiated in 1985. Therefore, none of the risks Dr. Smith sought to protect against had occurred, either. In an action on contract, a cause of action accrues upon a defendant’s failure to perform at the time and in the manner contracted, and a statute of limitations begins to run when a suit may be maintained. Davis v. Laclede Gas Co., 603 S.W.2d 554, 555 (Mo. banc 1980).
Furthermore, appellants herein could not have been aware of any damage when the policies were delivered in 1979, because Dr. Smith (whose interest in this litigation has been assumed by appellants) is entitled to rely on the insurance experts at RBH to procure the requested coverages. Martin v. Crowley, Wade & Milstead, Inc., 702 S.W.2d 57, 58 (Mo. banc 1985). As with any relationship between a layman and an expert, the layman has no duty to double-check the expert’s work. Id.
For the same reason, this cause of action could not have accrued when suit was filed in 1985 because Dr. Smith still had a right to rely upon RBH’s expertise. It would be absurd to require lay parties, in addition to hiring a professional, to also have to make their own independent layman’s investigation to ascertain whether their professional agent had done its job properly. Thorne v. Johnson, 483 S.W.2d 658, 663 (Mo.App., K.C.D.1972). Dr. Smith is no exception to this reasoning. He had no way of knowing, nor should he have known, that he would be damaged directly (i.e. personally) when the suit was filed in 1985.
Our reasoning here is in accord with the cases of Southern Cross Lumber v. Becker, 761 S.W.2d 269 (Mo.App., E.D.1988) and Dixon v. Shafton, 649 S.W.2d 435 (Mo. banc 1983). In each of these cases, the court reasoned that the right of action accrued when the party first saw he would sustain damage. In Southern Cross Lumber, this occurred when a lien waiver was used to defeat Southern Cross Lumber’s *923claim for a mechanic’s lien, not when the lien waiver was signed. Southern Cross Lumber, 761 S.W.2d at 271. In Dixon, the parties sustained ascertainable damage when their attorney informed them of his mistake, not when the mistake itself was made. Dixon, 649 S.W.2d at 438.
In the case before us, Dr. Smith had every right to expect he was insured until notified to the contrary. We are persuaded by appellants’ contention that the cause accrued when coverage was denied. The record is unclear regarding when this notification occurred, if it occurred at all. It has long been the rule that the burden of establishing the statute of limitations defense lies with the party who asserts it. Southern Cross Lumber, 761 S.W.2d at 271. Because the above date does not appear in the record, respondents’ statute of limitations defense fails for lack of proof. Therefore, we must reverse the trial court’s grant of summary judgment in favor of respondents, and remand this issue for further proceedings.
CONTRACT REFORMATION CLAIM
Appellants also filed suit in equity for reformation of the insurance contract. Appellants’ petition asks the court to write the allegedly requested coverage into the insurance policy. Respondents once again assert only that the statute of limitations has lapsed, and appellants’ claim is time barred. On this issue, we agree with respondents.
All parties agree the applicable statute of limitations regarding contract reformation is ten years. RSMo § 516.110 (1986); See Citizens Bank of Festus v. Frazier, 352 Mo. 367, 177 S.W.2d 477, 482 (1944). Regarding when the cause of action accrues, the Missouri Supreme Court has held the limitations period begins running as soon as the party can sue. Stark v. Zehnder, 204 Mo. 442, 102 S.W. 992, 995 (1907). In Stark, the party seeking reformation acquired the right to sue when the mistake was made; it need not wait until an ancillary dispute arises. Id. The court’s reasoning in Stark is quite specific:
[T]he plaintiffs’ right to have the contracts reformed accrued as soon as the mistake occurred. They were not compelled to wait until [defendant] should make a breach in his promise to pay.... If, the next day after these contracts were delivered, the plaintiffs had filed a suit in equity to have them reformed, based on the same allegations that are now made, it would have been no valid plea, either in bar or abatement, for the defendant to have answered that the suit was premature. Id.
Some years later, the Eighth Circuit cited Stark when deciding a similar case. Kithcart v. Metropolitan Life Ins. Co., 150 F.2d 997 (8th Cir.1945). The Eighth Circuit arrived at the same resolution as the Missouri Supreme Court, and for the same reasons. Based on the Missouri Supreme Court’s controlling opinion in Stark, we hold that judgment on the pleadings was appropriately entered in favor of respondents on the contract reformation claim. In the last paragraph of its brief, respondent Momedico contends appellants’ suit should be disallowed due to unclean hands and laches. Though the subject of equitable estoppel may bear closer scrutiny, we note that it was not raised at the trial court level, nor was it adequately briefed. We, therefore, cannot review this issue, as it is not properly before us.
The judgment of the circuit court is affirmed in part, and reversed in part.
SMITH, J., concurs in part and dissents in part in separate opinion. BLACKMAR, Senior Judge, concurs in part and dissents in part in separate opinion.. Keith Nuspl will hereafter be referred to as "Keith”. Use of his first name is for clarity only; no disrespect is intended.