Edith Foster is totally disabled as a result of a fall suffered when she tripped over a heavy box left on the floor of the office of her employer, Howrey & Simon. Her claim for workers’ compensation was upheld, after exhaustive discovery and a full and fair administrative hearing, at two levels of the District of Columbia Department of Employment Services (DOES). The only issue before this court is whether Ms. Foster’s claim should be barred because of untimely notice of the injury to the employer. The agency determined the notice requirement was satisfied because the employer had actual knowledge of her injury. Finding the agency’s construction of the statute reasonable, we affirm.
I
D.C.Code § 36-313 (1981) provides that a claimant must give written notice to the employer within thirty (30) days of first becoming aware of an employment-related injury. There are two exceptions to this rule, however. D.C.Code § 36-313(d)(l) provides that failure to give written notice will not bar a claim if the employer had knowledge of the injury and its relationship to the employment, and the employer has not been prejudiced by failure to give notice. D.C.Code § 36-313(d)(2) provides that the failure to give written notice may be excused for some other reason, such as that notice could not be given.1
At the first level of the administrative process, a hearing examiner concluded that Ms. Foster’s claim should not be barred because her good faith effort to give notice, coupled with the failure of her employer’s agent to understand the notice, constituted a satisfactory reason why proper notice was not given. At the second level, the director of DOES disagreed with the hearing examiner’s reasoning for excusing failure of timely notice under § 36-313(d)(2), but concluded that because How-rey & Simon had actual notice of the injury and its relationship to the employment and was not prejudiced by the late filing, the employee’s claim was not barred because of § 36-313(d)(l). DOES found that an employer has actual knowledge of an injury and its relationship to employment when “there is an incident at work witnessed by an employer’s representative which ultimately results in an injury ... [and] both the injured employee and the employee’s representative had underestimated the seriousness of the incident at the time of the incident.” The director’s interpretation of the “knowledge exception” to the formal notice provision of the Act is not only consistent with the statutory language of the Act, but is also in harmony with the purposes of the notice provision and with *256the rule preferred in most jurisdictions.2 For these reasons, we find the agency’s construction of the statute reasonable and affirm.
Edith Foster worked as an accounting clerk for Howrey & Simon. On January 18, 1983, Ms. Foster was carrying some papers when she walked around a file cabinet and tripped over a heavy box. Breaking her fall somewhat with her right hand, she landed on the carpet with a loud crash and with her right thigh over the box. Several people, including Ms. Foster’s supervisor, came over and asked her if she was all right. She indicated that she was “shook up,” but that she thought she would be all right. Ms. Foster returned to her desk for awhile, but then went upstairs to a room with a bed in it to lie down for awhile.
During the next month, Ms. Foster began to feel pain in her hip and leg. She sought medical attention for the pain, and was given arthritis medication. Although she continued to work, and her doctor tried different treatments, claimant’s pain worsened.
Ms. Foster stated that she discussed her condition with her co-workers as well as her supervisor, Mr. Lucien Richard, and Ms. Jan Dietrich, employer’s manager. Sometime during the spring of 1983, Ms. Foster told her supervisor that her left hand had been hurting her ever since her fall, though she was not sure if there was a connection, and that one of her legs bothered her. In May 1983, claimant requested part-time employment from Mr. Richard, and discussed her leg and hip problems with reference to the January fall. Ms. Foster also requested part-time work status from Jan Dietrich. Ms. Foster explained that her need to switch to a physically less demanding part-time schedule stemmed from difficulties she was experiencing in sitting in one place for any length of time due to the pain in her back and leg. She told Ms. Dietrich that she thought her leg and hip problems were the result of her January fall.
In mid-June she told Mr. Richard that she was going into the hospital for testing. Claimant testified that she explained to Mr. Richard that the testing was to determine the cause of her physical problems and that the condition might be related to her fall in January. Before the testing could begin, however, claimant’s condition deteriorated and she was placed in the hospital in traction. Ms. Foster was referred to an orthopedic specialist by her doctor, and on June 14, 1983, when she was in the hospital, the orthopedist told claimant that her fall in January caused the pain in her leg and hip because she had suffered a back strain.
Upon her return from the hospital, claimant wore a brace. She could not sit up straight or walk straight. Ms. Foster changed office chairs numerous times, and tried to sit with a pillow to ease her pain. She told Mr. Richard that she had been advised by a doctor for the first time that her pain was related to the January injury. Ms. Foster stopped working after about a week.
Richard and Dietrich gave different accounts of claimant’s fall and her oral notice. Richard denied that claimant ever spoke to him about her fall after the accident. Dietrich stated that she did not learn that Ms. Foster’s injuries were work-related until she received a phone call from employer’s insurer, Atlantic Mutual Insurance Company, on August 16, 1983. This testimony conflicted with Dietrich’s earlier testimony that Ms. Foster had spoken with her about a back problem when inquiring about the possibility of part-time work in the spring of 1983. The hearing examiner specifically credited Ms. Foster’s testimony concerning her recall of what she had told Richard and Dietrich, calling her a “very *257credible” witness.3 The examiner rejected Mr. Richard’s testimony to the extent it conflicted with Ms. Foster’s version of her fall. She noted that Richard had “an interest in trivializing the incident in order to justify his own failure to report the injury.”
II
According to Professor Larson in his treatise The Law of WORKMEN’S Compensation, the purpose of notice provisions is two-fold: “First, to enable the employer to provide immediate medical diagnosis and treatment with a view to minimizing the seriousness of the injury; and second, to facilitate the earliest possible investigation of the facts surrounding the injury.” A. Larson, The Law of WORKMEN’S Compensation § 78.10 at 15-81 (1983). Where, as here, the employer actually witnesses the incident, no further investigation is necessary. If the employee ultimately pursues a compensation claim, the employer has all the facts that would be necessary to confirm or controvert the employee’s version of what happened and to dispute, if appropriate, the causal connection between the incident and the subsequent disability. Similarly, if the employer knows as much about the symptoms as the claimant does, it has all the facts necessary to consider, when the claim is ultimately made, whether the disability is work-related and whether the extent of the injury is consistent with the facts of the occurrence.
Finally, if both employer and employee underestimate the seriousness of the injury, and neither believes that immediate medical treatment is necessary, the interest of the employer in having the knowledge necessary to facilitate prompt medical attention is not disserved. There is no cognizable prejudice to the employer if the claimant’s injury was not aggravated because of the employer’s inability to provide an early diagnosis and treatment and the employer was not hampered in making his investigation and preparing the case. Here, there was no apparent reason to seek immediate medical attention (neither Ms. Foster nor Mr. Richard were aware of the extent of her injuries). Moreover, because Mr. Richard actually witnessed the fall, the employer was aware of the circumstances surrounding the injury later discovered, thus obviating the need for an “early investigation.”
The better-reasoned decisions in the caselaw cited in Professor Larson’s treatise support the finding of actual knowledge here. For example, in Beatrice Foods Co. v. Clemons, 54 Ala.App. 150, 306 So.2d 18 (1975), the claimant fell while alighting from his employer’s truck. He reported orally to his supervisor that he had fallen, but the supervisor made no inquiry as to the extent of his injury or if he needed to see a doctor. The supervisor stated that he made no written report, nor was he aware that such a report was necessary. Claimant returned to work when scheduled and continued to work regularly until some eight months after the fall. His back injury, evidenced by increasing pain, eventually required surgery. The court in Beatrice Foods found the employer had actual knowledge. See also McElhannon v. St. Paul Fire & Marine Insurance Co., 141 Ga.App. 169, 233 S.E.2d 28 (1977) (claimant felt sudden pain in her back, leg and foot while carrying sixteen pounds of paper; court found actual knowledge where employer knew of claimant’s pre-existing injury and observed aggravation of pre-existing injury while on the job); Yerhart v. Geo. A. Hormel & Co., 303 Minn. 540, 225 N.W.2d 851 (1975) (foreman had sufficient knowledge of the facts and circumstances of employee’s injury to put him on inquiry that the disability was work-related, where claimant operated forklift truck over holes in the floor of his work area); and Moore Electric Co. v. Industrial Commission, 83 Ill.2d 43, 46 Ill. Dec. 149, 413 N.E.2d 1262 (1980) (employer had actual knowledge where claimant asserts he gave oral notice of fall from ladder and where employer *258was aware that claimant was experiencing pain and consulting doctors).
The agency’s finding of actual knowledge here is not only legally sound, it is logically sound. Accidents which appear minor at the time they occur may result in greater injury than anticipated. Courts often find actual knowledge in such circumstances. For example, in Korzeniewski v. M.W. Kellogg Co., 12 A.D.2d 570, 206 N.Y. S.2d 985 (1960), the claimant dropped a metal weight on his big toe. The foreman testified that he “put a bandage on it and [he] didn’t think anything about it.” The injured toe became gangrenous and was amputated about five weeks after the accident. The amputation wound thereafter became infected and claimant was totally disabled for some five months. The court found the employer had actual knowledge of the injury. Similarly, in N.L. Industries v. Childs, 150 Ga.App. 866, 258 S.E.2d 667 (1979) the employer was found to have actual knowledge where claimant hurt his thumb, but continued to work for several months thereafter without filing any claim for compensation. Claimant eventually became totally disabled and was admitted to the hospital for corrective surgery. See also Ragland Brick Co. v. Campbell, 409 So.2d 443 (Ala.Civ.App.1982) (actual knowledge of injury of leg sufficient to meet notice requirement with regard to both leg and back injury).4
Ill
This court has held time and time again that where there is broad delegation of authority to an administrative agency, we must give deference to a reasonable construction of the regulatory statute made by the agency. See Grayson v. District of Columbia Department of Employment Services, 516 A.2d 909, 912 (D.C.1986); McDaniels v. District of Columbia Department of Employment Services, 512 A.2d 990, 991 (D.C.1986); Hughes v. District of Columbia Department of Employment Services, 498 A.2d 567, 570 (D.C.1985); Gomillion v. District of Columbia Department of Employment Services, 447 A.2d 449, 451 (D.C.1982); Hockaday v. D.C. Department of Employment Services, 443 A.2d 8, 12 (D.C.1982); Thomas v. District of Columbia Department of Labor, 409 A.2d 164, 169 (D.C.1979). Because none of the policies underlying the notice provision are implicated in this case, and given that the director’s holding here expresses a rule that appears to be both generally recognized and preferred by Professor Larson in his treatise on workmen’s compensation, we find that far from being an unreasonable construction of the statute, the director’s construction is both reasonable and fair.
Affirmed.
. D.C.Code § 36-313 (1981) provides, in pertinent part:
(a) Notice of any injury or death in respect of which compensation is payable under this chapter shall be given within 30 days after the date of such injury or death, or 30 days after the employee or beneficiary is aware or in the exercise of reasonable diligence should have been aware of a relationship between the injury or death and the employment. Such notice shall be given to the Mayor and to the employer.
(b) Such notice shall be in writing, shall contain the name and address of the employee and a statement of the time, place, nature, and cause of injury or death, and shall be signed by the employee or by some person on his behalf, or, in case of death, by any person claiming to be entitled to compensation for such death or by a person on his behalf.
******
(d) Failure to give such notice shall not bar any claim under this chapter:
(1) If the employer (or his agent in charge of the business in the place where the injury occurred) or the carrier had knowledge of the injury or death and its relationship to the employment and the Mayor determines that the employer or carrier has not been prejudiced by failure to give such notice; or
(2) If the mayor excuses such failure on the ground that for some satisfactory reason such notice could not be given; or unless objection to such failure is raised before the Mayor at the 1st hearing of a claim for compensation in respect of such injury or death. (July 1, 1980, D.C.Law 3-77, Sec. 14, 17 DCR 2503.)
. The director’s conclusion is further buttressed by the principle, followed in this jurisdiction under the Longshore Act, that knowledge on the part of the employer will be found if the employer "has facts that would lead a reasonable man to conclude that compensation liability is possible." Stevenson v. Linens of the Week, 233 U.S.App.D.C. 1, 8, 688 F.2d 93, 100 (D.C.1982). Thus, section 20(b) of the Longshoreman’s Act creates a presumption that sufficient notice of the claim has been given. This applies'not only to written notice but to actual notice. Here, there was not evidence to overcome the statutory presumption.
. The hearing examiner did not discredit the testimony of Richard and Dietrich regarding claimant’s attempts to notify them, but found both failed to "get the message" about claimant’s injury.
. The state cases cited by the dissent to support its restrictive interpretation of actual knowledge turn on different facts than those present here. In Bagley v. Hotel Florence Co., 165 Mont. 145, 146-50, 526 P.2d 1372, 1373-74 (1974) the claimant's fall was not witnessed by the employer, and the claimant did not assert a link between the fall and the injury until almost three years after the fall. In the two other cases cited by the dissent, Kresge v. Holley, 104 Ga.App. 144, 146-47, 121 S.E.2d 182, 184 (1961) and Monks Excavating & Redi-Mix Cement v. Kopsa, 148 Colo. 586, 590-91, 367 P.2d 321, 323 (1961), the employer witnessed the accident, but the employee sought no immediate respite and remained silent about the effects of the accident. Specifically, in Monks Excavating, the claimant’s lack of reaction to his fall, his failure to make any mention of back difficulties over the next ten months, and his unique relationship with his employer was dispositive (the court noted that as employer's son-in-law, claimant was in a position to communicate even the slightest symptoms).