In these consolidated appeals,1 airline passengers or their survivors appeal from summary judgment in favor of Continental Airlines and a number of other air carriers on their claim for damages for failure to warn of the risk of Deep Vein Thrombosis (DVT) on international flights. They argue that the airlines’ refusal of requests to warn was an unexpected event and thus, an “accident” under Article 17 of the Warsaw Convention, because before their flights, the airlines’ trade organization, the English House of Lords, and airline medical officers had urged airlines to warn of DVT risks, and the airlines themselves had publicly represented that preventing passenger injury was a priority. However, we have already held that developing DVT in-flight is not an “accident,” Rodriguez v. Ansett Australia, Ltd., 383 F.3d 914, 917 (9th Cir. 2004), and that failing to warn about its risk is not an “event” for purpose of liability for an “accident” under Article 17, Caman v. Continental Airlines, Inc., 455 F.3d 1087, 1092 (9th Cir. 2006). Neither requests by public agencies, nor the airlines’ public commitment to safety, converts the failure to warn about DVT into an event or accident; the gravamen remains, at its core, a failure to warn. If there is no liability for failure to warn, there is none for failure to warn effectively. Accordingly, we affirm.

I

Between 2001 and 2004, passengers or their decedents purchased a plane ticket *959on an air carrier for an international flight during which they allegedly incurred injuries and, in five cases, death, which they attribute to DVT. Deep vein thrombosis is a medical condition in which a blood clot forms in the deep veins of the legs. Before their flights, the International Air Transport Association (IATA), the English House of Lords, and airlines’ own medical personnel had suggested that airlines warn passengers about DVT. For example, in December 2000, the British House of Lords published a report suggesting that airlines should make DVT information available through “high profile pre- and inflight preventive advice” as well as “active encouragement of in-flight mobility and preventive leg exercises.” In a magazine article, the chief medical officer of United Airlines, Dr. Gary Kohn, said that United takes extra safety steps and gives passengers tips on avoiding DVT. And in February 2001, the IATA issued a press release that stated, among other things, at the present time, there is no conclusive medical evidence supporting a connection of DVT with long distance travel; air carriers should warn passengers of the risk of DVT at the time of making reservations; and on board, airlines should encourage passengers to drink sufficient fluids, wear loose fitting clothes, avoid smoking and alcoholic beverages, and perform physical exercises in their seats. Air carriers generally put information about DVT on their websites and in inflight magazines. Air carriers also publically state that preventing passenger injury is a priority.

Air carriers moved for summary judgment, which the district court granted. The court concluded that Caiman mostly controlled, but that, to the extent passengers maintained that the airlines elected not to give warnings (or effective warnings), those decisions would be too remote from the embarking, disembarking, and on-board process for injury to be compen-sable under Article 17. The court allowed discovery into industry practice and individual airline policy, but rejected passengers’ Fed.R.Civ.P. 56(f) request for additional discovery.

Passengers timely appealed.

II

The United States is party to the Convention for the Unification of Certain Rules Relating to International Transportation by Air, commonly known as the “Warsaw Convention.” Oct. 12, 1929, 49 Stat. 3000, T.S. No. 876 (1934). The Convention provides uniformity with respect to documentation and certain procedural matters, and imposes limitations on liability. El Al Israel Airlines, Ltd. v. Tseng, 525 U.S. 155, 169, 119 S.Ct. 662, 142 L.Ed.2d 576 (1999); In re Aircrash in Bali, Indonesia on April 22, 1971, 684 F.2d 1301, 1307 (9th Cir. 1982). The “recovery for a personal injury suffered on board an aircraft or in the course of any of the operations of embarking or disembarking [an aircraft], if not allowed under the Convention, is not available at all.” Tseng, 525 U.S. at 161, 119 S.Ct. 662 (quotation and citation omitted).

Article 17 governs injury to persons suffered during international air travel and provides:

The carrier shall be liable for damage sustained in the event of the death or wounding of a passenger or any other bodily injury suffered by a passenger, if the accident which caused the damage so sustained took place on board the aircraft or in the course of any of the operations of embarking or disembarking.

Warsaw Convention, Art. 17.

The Convention itself does not define “accident,” but the Supreme Court did in Air France v. Saks, 470 U.S. 392, 105 S.Ct. 1338, 84 L.Ed.2d 289 (1985). An *960“accident” is an “unexpected or unusual event or happening that is external to the passenger.” Id. at 405, 105 S.Ct. 1338. Although “[t]his definition should be flexibly applied after assessment of all the circumstances surrounding a passenger’s injuries,” id., “when the injury indisputably results from the passenger’s own internal reaction to the usual, normal, and expected operation of the aircraft, it has not been caused by an accident, and Article 17 ... cannot apply,” id. at 406. In turn, the Court focused on the meaning of “event” in Olympic Airways v. Husain, 540 U.S. 644, 124 S.Ct. 1221, 157 L.Ed.2d 1146 (2004). There, a passenger and his wife were seated near the smoking section. The passenger had a history of anaphylactic reactions to smoke and asked a flight attendant to be moved away from it. The crew refused the request, and the passenger died in an apparent reaction to the smoke in flight. Even though the conduct amounted to inaction, the Court concluded that it could nevertheless be an “event” because “[t]he rejection of an explicit request for assistance would be an ‘event’ or ‘happening’ under the ordinary and usual definitions of these terms.” Id. at 655,124 S.Ct. 1221.

Based largely on this rationale, passengers here contend that it was equally unexpected and unusual for air carriers not to warn effectively about DVT because the airlines had been “requested” to do so by IATA, the English House of Lords, and airline doctors. However, an airline’s failure to warn a passenger about DVT is not an “event,” and thus not an Article 17 “accident.” Caman, 455 F.3d at 1092. It does not become one simply because public agencies have recommended, or “requested,” warnings.

Other courts, including those of signatory nations whose views are entitled to weight, are in accord. See, e.g., Blansett v. Continental Airlines, Inc., 379 F.3d 177, 180(5th Cir. 2004) (acknowledging that the IATA has recommended that airlines implement a schedule of instructions on the risks of DVT, and holding that Continental’s failure to warn of DVT was not an “unusual or unexpected event” and therefore not a qualifying “accident”); Povey v. Qantas Airways Ltd., (2005) 223 C.L.R. 189 (Austl.) (holding that the failure to warn of DVT is not an actionable “accident” under the Convention); Deep Vein Thrombosis and Air Travel Group Litig., [2005] UKHL 72, [2006] 1 A.C. 495 (U.K.) (same). Nor does the Federal Aviation Administration require warnings on DVT.

Passengers’ reliance on McCaskey v. Continental Airlines, Inc., 159 F.Supp.2d 562 (S.D.Tex. 2001), and Fulop v. Malev Hungarian Airlines, 175 F.Supp.2d 651(S.D.N.Y. 2001), is misplaced. Unlike in Caman, Rodriguez, and Blansett, injuries in both these cases (as in Husain) stemmed from specific health-based requests for help that were unheeded by airline crew. The passenger in Fulop had a heart attack on board, 175 F.Supp.2d at 664; in McCaskey, a stroke, 159 F.Supp.2d at 568; yet in neither case did the plane divert. Generalized requests by public agencies to warn are quite different from the particularized requests by individual passengers for assistance, and the airline’s response to them, at issue in these cases. Nor does our decision in Prescod v. AMR, Inc., 383 F.3d 861 (9th Cir. 2004), support passengers’ submission that a “promise” by air carriers to make passenger safety a priority is an “event.” There, an embarking passenger made a specific request— that a bag with medications and a breathing device stay with her on the flights ahead' — and the airline gave its word to honor this request. The airline then unexpectedly seized, and delayed, the bag. We concluded that seizing the bag was an “unusual and unexpected event” because doing so was contrary to the airline’s specific *961promise, and was external to the passenger for the same reason the refusal of assistance in Husain was external to the passenger. Prescod, 383 F.3d at 868. A failure to follow through on a promise to take care of a specific, health-related request, which was unexpected in Prescod because of the promise, does not mean that every injury to a passenger is an unexpected “event” simply because airlines have declared that avoiding injury to passengers is a priority.

Just as we found it unnecessary to decide how industry standards figure into the Article 17 analysis in Caman, it is unnecessary to do so here. Passengers present no substantial evidence of an industry standard with respect to warning about the risks of DVT.

Finally, to the extent that passengers fault the district court for having invoked Article 17’s space and temporal limitations, it was in response to their alternative position that the airlines “elected” or decided not to warn despite requests to do so. However, we cannot see how it matters whether, or when, a decision not to warn was made in this case as there was no duty to warn of DVT risks in any event.

Ill

Passengers submit that regardless of how we view their case as to others, the judgment must be reversed as to Singapore Airlines because Singapore violated its own safety policy. Passengers’ only submission in support is a newspaper article, which is hearsay. As there is no substantial evidence of Singapore’s policy, we need not (and do not) decide what effect, if any, an airline’s violation of its own policies would have on liability under Article 17.

IV

Passengers maintain that such DVT warnings as were given through videos, magazines, and in ticket packets, failed to notify them of the risks of DVT. This is beside the point, given our holding in Caman that the airlines have no duty to warn of the risks of DVT. Given no duty to warn, it follows that there is no duty to warn in any particular way.2

V

Yesmin A. Canterbury’s argument that summary judgment should be reversed on the ground that her declaration indicates that a U.S. Airways flight attendant prevented her from standing and moving around during flight, even if properly raised in the district court, lacks merit. There was nothing unusual or unexpected about this flight attendant’s instructions to Canterbury to remain seated, so this occurrence cannot constitute an Article 17 accident. See Witty v. Delta Air Lines, Inc., 366 F.3d 380, 385 (5th Cir. 2004) (“[A]ny warning that passengers should not stay in their seats, but should instead move about to prevent DVT, would necessarily conflict with any federal determination that, all things considered, passengers are safer in their seats.”).

VI

Passengers’ argument that additional discovery would have disclosed additional refused requests and disregarded statements establishing the necessity to warn of DVT, and that failure to do so was part of a cover-up of DVT risk, fails for essentially the same reasons. The district court permitted broad discovery into the *962airlines’ actual practices, warnings of the risks of DVT, and policies. Beyond this, discovery would be unlikely to produce any probative evidence.

AFFIRMED.