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On July 12, fire ripped through an entertainment venue in Bangkok, Thailand, killing 28, injuring scores more, and causing unimaginable terror for the 200 people inside. The investigation is in its early stages, but authorities are examining whether flammable materials, including inexpensive sound-proofing insulation and plastic ceiling decorations known to be highly flammable and extremely toxic, contributed to the rapid spread of flames and smoke.1
While heartbreaking catastrophes like these continue to occur, they are in large measure preventable. In February, Jonathan Nieman and I wrote about the horrific New Year’s fire in the Swiss resort town of Crans-Montana that claimed 40 lives, injured more than 100, and has many parallels to this most recent event. With that in mind, we’re reposting that piece in the hope that renewed attention to proven fire-safety measures can help prevent future tragedies.
by Jonathan Niemann and Tim Fletcher, Gen Re
February 25, 2026
In the early moments of 2026, a horrific scene rapidly unfolded near the Swiss resort town of Crans-Montana. In the basement bar of Le Constellation, New Year’s revelers, many of whom were teenagers, feted with typical glee. Joy soon turned to terror, however, as a fast-moving fire arose, likely from sparklers affixed to champagne bottles that ignited flammable acoustic ceiling foam overhead.1 Flames reportedly spread quickly, forcing dozens of panicked patrons to escape through the bar’s main entrance consisting of a narrow flight of stairs and a single exit door, creating a bottleneck as toxic smoke filled the bar.2
While the investigation remains ongoing, this much is known: at least 40 people were killed and more than 100 injured.
The unfolding investigation has led to criminal charges of homicide, injures, and arson by negligence being filed against Le Constellation owners Jaque Moretti and his wife Jessica Moretti.3 At this juncture, analysts and fire-safety experts advise that this tragedy reflects the hallmark pattern of a flashover, a scenario seen in past disasters, most notably the February 2003 The Station nightclub fire in West Warwick, Rhode Island that resulted in more than 100 fatalities and over 200 injuries.4 In that event pyrotechnics ignited combustible materials on the nightclub’s walls and ceiling, with contributing factors that included overcrowding and the “grandfathered” absence of an automatic sprinkling system.5
From those ashes emerged a transformation in modern fire-safety practices, with significant changes to national fire codes, enhanced sprinkler use, requirements for larger, outward swinging exits, the use of fire-retardant interior finishes, and tighter regulation of pyrotechnic use in public assemblies.6 These changes have saved lives in here in the U.S., yet Le Constellation reminds us that preventable fire-driven tragedies can still occur.
In the aftermath two questions spring to mind: What causes flashover events? What can insurers do to help prevent them?
Frightening in both their speed and lethality, flashovers occur when a burgeoning fire suddenly ignites much of the combustible surface in a room.7 The National Institute of Standards and Testing (NIST) describes “flashovers” as occurring when “surfaces exposed to thermal radiation reach ignition temperature [greater than 1100 degrees Fahrenheit] more or less simultaneously and, given sufficient availability of oxygen, fire spreads rapidly throughout the space, resulting in full room involvement or total involvement of the compartment or enclosed space.”8
Precursor |
Description |
|---|---|
|
Rollover |
Takes place “in enclosed spaces where accumulated superheated fire gases and unburned products ignite upon mixing with oxygen, producing brief, sporadic flames or "snakes" amid the smoke layer. Rollovers typically show bursts of flame at ceilings or doorway openings.”9 |
|
Thick Smoke |
Smoke that changes from dark brown to black can signal an imminent flashover, with more thickening smoke portending of a more dramatic flashover.10 |
|
Free-Burning Fire |
Fire grows in intensity as it consumes more fuel, and spreads upward by convection and radiation as temperatures soar.11 |
|
Intense Heat / Thermal Layering |
Stratification of air and fire gases into layers based on temperature, with the hottest of the gases accumulating near the ceiling of the compartment or room until they find an escape route.12 |
That fateful evening at Le Constellation offers powerful insights for insurers, and underscores actions they can take in response.
Strengthening and clearly defining underwriting protocols and guidelines are the most critical preventive steps. Any operation that uses indoor pyrotechnics or similar devices should be subject to heightened scrutiny and may be deemed ineligible for coverage. Verifying that all ceiling and wall materials are fire‑resistant and compliant with NFPA guidelines and relevant ASTM ratings should be standard practice. Mandatory underwriting inspections should be required at policy inception and at renewal and must include the collection and review of all maintenance records and building certifications.
Insurers must be acutely aware of how their risk truly operates and any increased hazards. Are there capacity requirements? Is employee fire safety training mandatory? Does the operation host any special events outside its normal activities? Are fire prevention and emergency evacuation plans in place? Developing a holistic view of the operation up front allows insurers to identify and implement appropriate mitigation measures before binding, measures that are critical to reducing the potential for a flashover.
Utilizing findings and data from fire-related claims and subrogation investigations to identify recurring ignition sources, building or maintenance failures, and human-induced factors, that can then be fed back into underwriting guidelines, inspection protocols, and policy conditions, can also be instrumental in the prevention of flashover-driven losses.
Insurers should support and mandate, where possible, building codes and construction methods that improve fire and flashover-resilient structures. Requiring automatic suppression systems is the most widely used and effective method for automatically controlling fires.13 Additionally, buildings constructed with well‑ventilated, fire‑resistant, or non‑combustible materials, equipped with automatic fire‑protection systems capable of early detection, supported by emergency lighting, and with unobstructed exits are foundational to flashover prevention and mitigation.
Offering premium discounts for structures within this class of business that comply with, or are upgraded to, NFPA standards and current fire/building codes incentivizes investment in flashover fire-resistant structures. Including policy terms and conditions that require active, maintained automatic sprinklers or smoke detectors, or that exclude unauthorized practices, are also measures insurers can take once the policy is bound.
Insurers can leverage their power and influence at the state and federal levels to lobby for stronger fire-safety and building codes, along with better oversight and enforcement. Partnering with fire‑protection organizations, code‑development bodies, and safety/insurance institutes is another way insurers can help shape the regulatory environment surrounding flashover prevention.
Education is one of the most powerful tools in preventing future flashover tragedies. Publications, blogs, social media posts, digital mailings, direct text messaging, webinars, conferences, and community outreach campaigns are all highly effective channels for raising awareness.
New and emerging fire technologies – such as Ting Fire Prevention, Atexon Spark Detection, Intenseye, Facility OS, drone inspection, 3D Modeling, and advanced fire detection and suppression systems – will be instrumental in paving the way to flashover mitigation and prevention. Insurers should invest in and embrace the next generation of fire‑prevention technologies to strengthen their portfolios and build books of business that are less susceptible to flashover events.
Insurers working with fire scientists and cause and origin investigators is another way to share information and transform past investigative data into future knowledge and awareness for flashover behavior and prevention.
Leveraging data analytics and AI offers a powerful way to identify patterns in fire incidents. By using machine learning to analyze causes, building layouts, vulnerable structures/materials, and fire‑prone areas/neighborhoods, insurers can harness predictive models that forecast future flashover outbreaks and behavior.
The Station nightclub flashover fire in Rhode Island became a turning point for modern fire safety reform in the U.S., driving major advancements in national fire codes. However, the deadly fire at Le Constellation in Switzerland is a sobering reminder that catastrophic, preventable fires can still occur.
Learning from these events and continually advancing industry practices strengthens our ability to help stop flashover tragedies before they happen. To learn more, please contact us or your Gen Re representative.
