Opinion for the court filed by Circuit Judge HENDERSON.
Dissenting opinion filed by Chief Judge MIKVA.
KAREN LeCRAFT HENDERSON, Circuit .Judge:Linda Wheeler Tarpeh-Doe (Linda) and Marilyn Wheeler, Linda’s mother and the legal guardian of Linda’s son, Nyenpan Tar-peh-Doe (Nyenpan), filed this action seeking damages against the United States under the Federal Tort Claims Act (FTCA), 28 U.S.C. § 1346(b) and §§ 2671 et seq., for the alleged negligent failure of Department of State personnel to supervise a staff doctor whose negligence allegedly caused Nyenpan irreversible neurological injury. Following a bench trial, the district court found in the plaintiffs’ favor and awarded them damages of $4,659,-487.57. See Tarpeh-Doe v. United States, 771 F.Supp. 427 (D.D.C.1991) (establishing liability and awarding damages of $901,-162.71); Order and Memorandum, C.A. No. 88-0270 (filed Mar. 20, 1992) (increasing damage award to current amount). The United States appeals the court’s finding of liability. Because we find no evidence that the Department of State breached a supervisory duty that caused the appellees’ injuries, we reverse the district court’s decision.
I.
The district court’s findings reveal the following material facts, supported by the evidence and largely undisputed.
In 1980 Linda, a certified public accountant, was hired as an accountant by the United States Agency for International Development (AID) and shortly thereafter was assigned to Monrovia, Liberia. She arrived in Monrovia on May 26, 1981, and almost immediately met and became romantically involved with Nyenpan “Ben” Tarpeh-Doe (Ben), an employee of the Liberian Ministry of Justice. In September 1981, Ben and Linda visited the United States Embassy health unit twice so that Ben could undergo various medical tests required before their planned marriage. On one visit, Linda mentioned to Dr. Theodore E. Lefton, the Regional Medical Officer assigned to the Embassy in Monrovia, that she was pregnant, a fact she had learned earlier in the month from a test administered by Dr. Kassas, a local physician whom Ben had recommended. Throughout her pregnancy Linda received regular prenatal care from Dr. Johnson, a local obstetrician and gynecologist, to whom either Dr. Lefton or Billie Clement, the Embassy nurse, had referred her for a gynecological problem the previous July. At no time during her pregnancy did Linda seek or receive care from Dr. Lefton.
On January 16, 1982 Ben and Linda were married and on May 18, 1982 Linda gave birth to Nyenpan in a local clinic, with Dr. Johnson present. After she was released from the clinic, Linda continued to see Dr. Johnson who examined both Linda and Nyenpan on May 25 and again on June 2. On each occasion he found them both in good health. Nevertheless, Linda fell ill the evening of June 2. When she showed no improvement by the following evening, Thursday, June 3, a friend called the Embassy health unit and requested medical assistance. Dr. Lefton was unavailable and Linda was visited instead by Dr. Feir, the Embassy psychiatrist, accompanied by Clement, the Embassy nurse. Dr. Feir gave Linda an examination and recommended she seek care that night from Dr. Johnson and visit Dr. Lefton at the Embassy the following morning. According to Linda’s friend, Clement commented at the time that “she didn’t think the baby looked right.” Id. at 436. Dr. Johnson visited Linda at 1:00 a.m. Friday morning and treated her for malaria, staph infection and mastitis. When Linda visited *122the Embassy health unit later that morning, Dr. Lefton administered ampicillin for mastitis and told her she could resume breastfeeding Nyenpan. It is unclear whether Nyen-pan accompanied her to the Embassy.
Later that day, when Nyenpan became lethargic and refused feeding, Linda and Ben took him to the clinic where he had been born and a local physician treated him with ampicillin. When Nyenpan showed no improvement three hours later, his parents took him to the emergency room at a private hospital where two local doctors treated him with an electrolyte solution for dehydration. At 9:00 a.m. the next morning, when Linda attempted to awaken Nyenpan for his feeding, he “ ‘became rigid’ in her arms for one to two seconds,” 771 F.Supp. at 436, and the Tarpeh-Does decided to take him to see Dr. Johnson. On the way, however, they encountered Clement who persuaded them to visit the Embassy health unit instead. En route Nyenpan once again became briefly rigid.
When the Tarpeh-Does arrived at the Embassy, Dr. Lefton examined Nyenpan almost immediately and administered gentamicin and procaine, both antibiotics. He told Nyenpan’s parents the child could be evacuated from Liberia on an 11:00 p.m. flight that evening. Dr. Lefton then sent for Dr. Van Reken, an American pediatrician unaffiliated with the Embassy. Dr. Van Reken responded immediately, arriving at the Embassy about 11:30 a.m. The two physicians examined Nyenpan and agreed that he had spinal meningitis. Upon Dr. Van Reken’s assurance that he could “make the baby well,” Dr. Lefton decided not to permit evacuation but instead to transfer Nyenpan’s care to Dr. Van Reken. Dr. Van Reken proposed admitting Nyenpan to John F. Kennedy Hospital (JFK) in Monrovia, a facility with conditions Ben had heard were “appalling.” Nevertheless, “[o]ver the parents’ objections, and with the knowledge and concurrence of Dr. Lef-ton,” Nyenpan was taken to JFK at around noon, accompanied by Dr. Van Reken, Clement, Linda and Ben. When, after a lengthy delay, Nyenpan was finally placed in a room at about 1:30 p.m., Dr. Van Reken and Clement left the hospital and Ben, following Dr. Van Reken’s instructions, visited a local pharmacy to purchase certain prescription drugs unavailable at JFK. Dr. Van Reken returned at about 4:00 p.m. and left instructions for Nyenpan’s overnight care. Linda, along with several friends, including Dr. Wit-ten, a physician whose husband was affiliated with AID, stayed overnight in Nyenpan’s room where they observed both rats and cockroaches moving about. Nyenpan, who was not visited by a hospital doctor from 9:00 p.m. until 6:30 a.m, developed a fever during the night and suffered additional seizures. Dr. Witten recommended giving him oxygen but upon inquiry the group was informed that the hospital’s only oxygen unit was already in use and that the Embassy had none of its own. Dr. Witten then administered valium to treat Nyenpan’s seizures.
Dr. Van Reken returned to JFK late the next morning and reluctantly agreed at the Tarpeh-Does’ insistence to transfer Nyenpan to another hospital. That afternoon Nyen-pan was moved to ELWA Hospital, a more sanitary and better run facility, and arrangements were made for a private nurse to attend him through the night. The district court found, however, that “it is more likely than not likely that Nyenpan was beyond hope of recovery at least by the time or shortly after his transfer to ELWA.” 771 F.Supp. at 441. When Nyenpan’s condition showed no improvement over the next few days, Dr. Van Reken agreed to have him evacuated. The evacuation was finally authorized on June 17,1982, and the Tarpeh-Does then flew to Colorado where Nyenpan was treated, without improvement, for two weeks at the University of Colorado hospital. After his release, Nyenpan lived with his mother for over a year until she was again assigned overseas duty. Because Nyenpan was unable to accompany her, the family had him admitted to the Wheat Ridge Regional Center in Colorado and Linda’s mother was appointed his guardian. The trial court found that Nyenpan will have to remain at Wheat Ridge “for the foreseeable future” and, based on a doctor’s deposition testimony, characterized Nyenpan’s condition at the time as follows:
[H]e receives extensive care. He has no independent skills- He has no functional control over his arms and legs, *123though he can move them.... He is blind. He continues to have ten to twelve seizures a year.... Care providers feed and dress him.... They also turn him every hour or two to prevent skin breakdown. ... In addition, they sometimes give him baths or massages, read him stories, or take him outside in a wheelchair.... He does not communicate in any meaningful way but responds positively to the care providers who are familiar to him.
771 F.Supp. at 439 (record citations omitted).
On January 31, 1984, the appellees filed an administrative claim with the Department of State, alleging negligence by government officials in both Liberia and the United States. The State Department denied the claim and the appellees then filed this action under the Federal Tort Claims Act against the United States and the Secretary of State, alleging negligence by State Department officials in Washington, D.C.1 As noted above, the district court found in the appellees’ favor and awarded them damages of $4,659,487.57. The appellants challenge that award on two grounds: (1) the Government is immune from liability under the “discretionary function” and the “foreign country” exceptions to the FTCA2 and (2) the appellees failed to establish, and the district court to find, any breach of a duty that caused their damages. We conclude the district court’s judgment must be reversed on the second ground and, accordingly, do not address the first.
II.
Tort liability under the FTCA is determined according to the law of the state where the alleged acts or omissions occurred. Kugel v. United States, 947 F.2d 1504, 1508 (D.C.Cir.1991) (citing 28 U.S.C. § 1346(b)); Red Lake Band of Chippewa Indians v. United States, 936 F.2d 1320, 1325 (D.C.Cir.1991). Thus, as the parties here agree, whether the government can be held liable for the appellees’ injuries must be resolved under District of Columbia tort law. The appellees prevailed below under a theoiy of negligent supervision, asserting that State Department officials were aware that Dr. Lefton was not properly attending to his duties and should therefore have supervised him more closely to ensure he was available to treat Nyenpan. The District of Columbia recognizes the tort of negligent supervision as formulated in the Second Restatement of Agency:
A person conducting an activity through servants or other agents is subject to liability for harm resulting from his conduct if he is negligent or reckless:
(a) in giving improper or ambiguous orders or in failing to make proper regulations; or
(b) in the employment of improper persons or instrumentalities in work involving risk or harm to others;
(c) in the supervision of the activity; or
(d) in permitting, or failing to prevent, negligent or other tortious conduct by persons, whether or not his servants or agents, upon premises or with instrumen-talities under his control.
Restatement (Second) of Agency § 213 (1957), quoted in Murphy v. Army Distaff Found., Inc., 458 A.2d 61, 64 (D.C.1983); see also International Distrib. Corp. v. American Dist. Tel. Co., 569 F.2d 136, 139 (D.C.Cir.1977) (applying District of Columbia law and citing § 213 as authority for tort of negligent supervision). Of course, as in any negligence action, a plaintiff seeking to establish negligent supervision “bears the burden of presenting evidence ‘which establishes the applicable standard of care, demonstrates that this standard has been violated, and develops a causal relationship between the violation and the harm complained of.’ ” Morrison v. MacNamara, 407 A.2d 555, 560 (D.C.1979) (quoting Kosberg v. Washington *124Hosp. Center, Inc., 394 F.2d 947, 949 (D.C.Cir.1968)). We conclude the appellees here did not sustain their burden of demonstrating the requisite causal relationship between any breach of duty by the State Department and the appellees’ injuries. As the district court recognized, the appellees were required to establish, at a minimum, that the alleged inadequate supervision of Dr. Lefton was a “substantial factor” in causing Nyen-pan’s irreversible condition. See Daniels v. Hadley Memorial Hosp., 566 F.2d 749, 757 (D.C.Cir.1977) (“[T]he plaintiff must show that the defendant’s deviation from the standard of care was a ‘substantial factor’ in bringing about the harm complained of.”); see also Lacy v. District of Columbia, 424 A.2d 817, 819-21 (D.C.1980) (“The substantial factor test ... is part of the District’s law of negligence.”). This they failed to do.
The district court found, and the record supports, that State Department officials were on notice that Dr. Lefton’s “attitude” and “availability” enjoyed a poor reputation among other United States citizens in Monrovia. Most tellingly, a State Department team that inspected the Embassy in February and March 1982 reported “widespread discontent with Dr. Lefton’s performance” and “dissatisfaction with Dr. Lefton’s attitude and availability.” The team characterized “the magnitude and intensity of the complaints” as “unprecedented in their experience” and specifically cited Dr. Lefton’s “insensitivity, aloofness, lack of sympathy, lack of ... bedside manner, and also frequent unavailability.” Thus, the Department may well, as the district court found, have been under a duty to take steps to improve Dr. Lefton’s availability and attitude. The Department may also have breached that duty. There is no evidence, however, that such a breach was a substantial factor causing Nyenpan’s current condition or the injuries flowing therefrom. Accordingly, we conclude the district court’s findings on causation were clearly erroneous under rule 52(a) of the Federal Rules of Civil Procedure and must therefore be reversed. See Red Lake Band of Chippewa Indians v. United States, 936 F.2d 1320, 1324-25 (D.C.Cir.1991).
The district court concluded that “Dr. Lefton’s negligent actions and omissions proximately caused Nyenpan’s injuries,” 771 F.Supp. at 452, and that the Washington defendants should be held liable for having “ ‘[permitted] or [failed] to prevent negligence or other tortious conduct by persons ... under [their] control,’ ” namely Dr. Lef-ton, id. at 454 (quoting Restatement (Second) of Agency § 213). Nevertheless, the court assigned no precise cause to Nyenparis deterioration and identified no single State Department omission that more likely than not permitted such a cause to occur. In fact, the court affirmatively acknowledged that it is “difficult to determine with any degree of certainty the true cause of the infant’s failure to recover.” 771 F.Supp. at 427.3 It is nevertheless clear from the record that the appellees attempted at trial to attribute Nyenpan’s deterioration to misdiagnosis and mistreatment by Drs. Lefton and Van Reken. The appellees’ experts testified that the two doctors incorrectly treated Nyenpan with antibiotics appropriate for Gram positive meningitis when in fact Nyenpan suffered from *125Gram negative meningitis. See 771 F.Supp. at 439-40.4 Even if this testimony supports a finding of negligence by the two physicians, such medical negligence would not have resulted from any breach of duty by State Department officials in Washington. Those officials were on notice only of Dr. Lefton’s poor “availability” and “attitude”; they had no reason to question his medical competence.5 They were therefore under no special duty to supervise Dr. Lefton’s medical decisions or treatment.
By the same token, there is no evidence that, had the Department taken steps to ensure Dr. Lefton’s availability or improve his attitude, as the district court found them bound to do, Nyenpan’s medical treatment or condition would have been any different. The district court concluded the “[d]efen-dants could and should have directed Dr. Lefton to focus more attention on his responsibilities and to make himself available in the evenings and on weekends,” 771 F.Supp. at 453, and identified four periods in which Lef-ton was not available to treat, or inattentive to, Linda or the child: (1) throughout Linda’s pregnancy when she was under the exclusive care of Dr. Johnson, with no follow-up by Lefton himself — the court’s assumption being that had Lefton been more attentive during this time Linda would have been more likely to consult him sooner, perhaps when she first fell ill on June 2, and obtain preventative advice that might have benefitted Nyenpan; (2) the evening of June 3 when Linda was attended by Dr. Feir, the Embassy psychiatrist, because Lefton was not available, and Clement observed she didn’t think Nyenpan “looked right”; (3) the morning of June 4, when Lefton actually treated Linda and failed to inquire after or examine Nyenpan; and (4) the period June 5-6 when Nyenpan was left entirely in Van Reken’s care with no inquiry from Lefton. The record contains no competent evidence, however, that any of the alleged inattentiveness caused Nyenpan’s condition or that greater vigilance during these times would have altered the ultimate result. There is no expert evidence that any preventative advice offered on June 2 or 3 might have averted the onset of meningitis altogether. The district court suggested that breastfeeding “might have caused or increased the child’s exposure to infectious bacteria,” but there is no expert evidence that breastfeeding was or might have been the cause of Nyenpan’s condition and, in any event, Linda ceased breastfeeding while she was ill. Id. at 436.6 Nor is there any evidence that, had Lefton been available on June 3, he could then have diagnosed, or more importantly correctly diagnosed, Nyen-pan’s condition or that earlier diagnosis would have prompted him to pursue a different course of treatment or would have slowed Nyenpan’s deterioration. Finally, there is no competent evidence that the substandard conditions at JFK, namely the infestation, medical inattention and lack of oxygen, worsened Nyenpan’s condition.
In short, even if Nyenpan’s current condition may have been caused in part by Dr. Lefton’s negligence, it was not the result of any failure by State Department officials to more closely supervise Dr. Lefton’s availability or attitude.7 Under the facts here, Dr. *126Lefton’s negligence, if any, was medical in nature and as such not preventible by any supervisory measures the Washington officials may have been under a duty to take.8 Accordingly, the government cannot be held liable for negligent supervision.
For the preceding reasons, the judgment of the district court is
Reversed.
. The appellees were precluded from suing for negligent acts or omissions occurring in Liberia because of the FTCA’s "foreign country” exception. See infra note 2 & accompanying text.
. These exceptions bar recovery, respectively, for "[a]ny claim ... based upon the exercise or performance or the failure to exercise or perform a discretionary function or duty on the part of a federal agency or an employee of the Government, whether or not the discretion involved be abused," 28 TJ.S.C. § 2680(a), or "[a]ny claim arising in a foreign country,” id. § 2680(k).
. The court made this concession while asserting that "D.C. courts have established that where a defendant’s acts or omissions create uncertainty as to whether, had the defendant acted otherwise, the outcome would have been more favorable to the plaintiff, that uncertainty does not provide a defense against the plaintiffs showing of proximate cause.” 771 F.Supp. at 453. It is true that when, as is often the case in medical malpractice actions, a defendant's negligent act or omission makes it more difficult to determine what the medical outcome would have been but for that negligence, the plaintiff’s burden of demonstrating a favorable outcome may be lightened. See Daniels v. Hadley Memorial Hosp., 566 F.2d 749, 757 (D.C.Cir.1977); Ascher v. Gutierrez, 533 F.2d 1235, 1238 (D.C.Cir.1976). In such a case, however, the plaintiff's burden of first establishing a negligent act or omission that could have caused an unfavorable outcome remains unchanged. In Daniels, for example, the plaintiff presented competent medical testimony that the plaintiff's condition "could have been medically corrected” had the emergency medical team acted within three minutes. 566 F.2d at 758. Numerous medical personnel testified about the importance of respiration therapy, particularly in averting immediate patient deterioration. Here, no medical expert identified what specific actions could have been taken in the June 3-5 period to avert Nyenpan’s deterioration. The district judge, while deserving of deference to sound legal judgments based on the evidence, cannot sit as a medical expert to fill the gap.
. Both are forms of bacterial spinal meningitis, but the two are caused by different bacteria. Gram positive by staph or strep and Gram negative by salmonella, and treated with different antibiotics. See 771 F.Supp. at 439-40.
. The Department’s inspection team reported no complaints about his medical expertise and in fact its leader "emphasized that the team was not qualified to evaluate Dr. Lefton’s medical competence from a technical standpoint.” 771 F.Supp. at 432. In addition, the then Medical Director of the State Department’s Office of Medical Services stated he "knew Dr. Lefton as a ‘bright young physician who was astute and competent' ’’ and "had ‘admired his acumen” in annual medical meetings.' ” Id. at 434 (record citations omitted).
.In addition, when Lefton did treat Linda on June 4, he advised her to resume breastfeeding, id. at 436 — there is no reason to believe he would have recommended the contrary one or two days earlier.
. While it is conceivable that immediate evacuation on June 5 might have altered the outcome, it is sheer speculation that Dr. Lefton’s decision not to evacuate in any way resulted from the State Department’s failure to monitor more closely his availability or attitude. Dr. Lefton in fact was present and treating Nyenpan when he made that decision and cited specific medical reasons for it. See id. at 441 ("Dr. Lefton stated that he did not want to evacuate the baby because of the risk of lack of oxygen on the plane while the baby *126was having a seizure.... He clarified that intu-bation (insertion of a tracheal tube) during a seizure would be more difficult in a plane.”) (record citations omitted).
. Thus, even had the Department "imposed additional reporting requirements” such as that Lef-ton "report any serious illness immediately by telephone or telegram," as the district court suggested it should have done, see 771 F.Supp. at 453-54, there is no reason to suppose such a policy would have ensured closer medical supervision by Lefton here or, if it did, that his medical diagnosis and treatment, or the consequences thereof, would have been any different.