Concern spreads over intense parking garage fires

Parking garages used to be on the fringes of commercial property fire risk: Adjacent to the action, but rarely stirring up much trouble themselves. Lately, though, a handful of high-intensity, fast-spreading, hard-to-extinguish fires in parking garages have drawn unprecedented attention to both the garages and their newer occupants: modern cars with more plastic and electronics than ever before, including an increasing number of electric vehicles and, sometimes, EV battery charging stations.

In August, a fire in a South Korea apartment complex’s underground garage burned for more than eight hours, reaching temperatures of 2732 degrees Fahrenheit (1500 degrees Celsius). The fire damaged nearly 900 vehicles and left 23 people suffering from smoke inhalation before firefighters were able to suppress it.

Fires in large parking garages remain relatively infrequent. But the South Korean garage fire and a handful of other garage conflagrations have made global headlines in the past five years due to new characteristics such as rapid spread from vehicle to vehicle, extremely dense and toxic smoke, and exceptionally high heat that can complicate firefighting and cause severe economic losses. Those fires include two in England, one at Liverpool Echo Arena in 2018 and another at Luton Airport in 2023, as well as another at Norway’s Stavanger Airport in 2020.

These fires have drawn new attention to how modern vehicles and parking structures — including automated car stackers popping up in congested metropolitan areas — may require a reclassification of fire hazard levels in parking garages and modifications to fire risk management tactics.

“This is an emerging risk we’re focused on,” said Bill Ingram, Vice President of Technical Operations for Zurich Resilience Solutions. “At this point there’s limited loss history and limited test data replicating modern vehicles and modern environmental conditions, so there’s some debate and variation over risk management approaches. But there’s not a debate that intense fires are happening. We continue to see that this risk is real.”

What’s causing parking garage fires?

The fire risk profile associated with cars today has changed in notable ways. One of the biggest hazards may not be the first that comes to mind. It’s the fact that modern cars of all types — not just EVs but also those with internal combustion (ICE) engines — have more plastic components than in the past, partly in an effort to reduce weight and enhance fuel efficiency as legal regulations evolve. In 2021, plastics accounted for approximately 411 pounds of the average vehicle’s total weight ­— about 9.6 percent — compared with less than 3 percent in the 1970s, according to the National Fire Protection Association.²

This higher plastic content has the potential to heighten the combustible energy in a fire, “potentially leading to higher heat release rates, longer burning durations and greater risk of fire spread in parking garages compared to older vehicles,” according to the NFPA.

All vehicles — whether they have lithium-ion batteries, hydrogen fuel cells, internal combustion or diesel engines, or some hybrid — can ignite fires for a variety of reasons. But fires in a garage where EVs are parked can affect fire behavior. Suppressing an EV-related fire can take twice to three times as much time as suppressing an ICE vehicle fire, the NFPA says, and doing so may require exponentially more water.

Both EVs and ICE vehicles present fire risks. The causes in EVs may be a short circuit, a puncture, overheating, overcharging or over-discharging, the NFPA says. The causes in ICE vehicles may be fuel or oil leaks, overheating, worn-out parts or loose electrical components, the NFPA says.

Do EVs increase garage fire risks?

Batteries in EVs can speed up the spread of fire, among other things.

“When you combine lithium-ion batteries and plastic,” Ingram said, “fires have the potential to cause greater damage, jumping to other vehicles very rapidly. The fire can burn so hot or for so long, or both, that it can potentially impair the concrete and rebar structure of the garage. That can potentially increase the risk of collapse.

Enclosed, underground garages can complicate both fire response and recovery. In an open-air garage, more of the heat can escape in a fire, Ingram said. But a fire is typically more intense and tougher to put out when it’s in an enclosed parking structure or below ground. Even after it’s extinguished, if there is a business or residences above the garage, “you can’t just lift the building above it out of the way to rebuild the garage. Because of that, you can see total losses and significant costs as a result of a fire.”

Reignition potential is higher for EV fires than for ICE fires, the NFPA says. It recommends that, after a fire, EVs be towed and placed 50 feet away from surrounding structures due to that reignition risk.

Stephen Penwright, Large Property Technical Director for Zurich North America, said evolving risks in parking garages are driving up loss expectancies, which can in turn affect the insurance capacity that carriers are willing to deploy.

“If the parking garage is separated from the main building or asset, the risk is sometimes more manageable,” Penwright said. “But the situation becomes particularly concerning when a garage is connected to or below the main building. When you think of a parking garage fire, you may not think of business interruption loss, but it’s a very real possibility if the parking structure is connected to a business, where ingress and egress may be impeded in the event of a fire.”

Smoke generated from lithium-ion batteries can require special treatments to clean up before the usual occupants can return as well.

The evolving fire dynamics have prompted some revisions and debate over the fire hazard classification that parking garages should have today. The variables are influencing development of new recommendations to mitigate the risk.

What’s being done to mitigate garage fire risks?

“There wasn’t a big push to sprinkler garages in the recent past, because it wasn’t where perceived risks were,” Penwright said. “That’s evolving, with growing awareness of loss exposures that used to be inside the building, such as at a casino or hospital, now moving to outside the building, which we used to view as fairly benign.”

In the past two years, the NFPA has elevated the fire hazard classification for parking structures and has called for sprinklers to be installed in all new parking structures, regardless of size, whether open air or closed.³ (The revision doesn’t apply to existing garages.) The NFPA also has adjusted some of its recommendations for sprinkler density.

Other organizations are making similar adjustments. The International Building Code in 2021 added a requirement for sprinklers in all new open parking garages over 55 feet in height or with over 48,000 square feet of fire area.⁴

Recommendations will continue to develop and evolve, Ingram and Penwright said. Some insurance providers consider the fire hazard to be a level above even the updated classification from the NFPA, which is working on more testing and research replicating modern scenarios.

“Existing data indicates that sprinklers can control fires and limit them to the initial vehicle, though the optimal design density is still unknown,” the NFPA said. “More research is needed to properly design sprinkler systems to prevent vehicle-to-vehicle fire spread in parking garages.”

Data is particularly scarce for automated garages that involve stacker structures with multiple tiers of cars stacked close to each other. These are increasingly common in urban centers where parking space is at a premium. Similar concerns have been discussed regarding “too tall, too dense” warehouse storage.    

Are more sprinklers recommended?

While sprinklering can represent a cost for businesses, Zurich regards sprinklering garages as a smart investment, given the severity of damage that parking garage fires have caused. Ingram said Zurich Resilience Solutions currently recommends sprinklering parking garages on any level that has a roof above it, even if the structure has walls that are open to the outside air.

Fire risk is particularly concerning in certain industries such as auto manufacturing and auto dealerships that service vehicles.

Zurich offers property and casualty insurance to auto dealers and shares information on the risks associated with EV batteries and cautionary steps to reduce fire risk to their dealerships. These steps include immediately returning defective, damaged or spent EV batteries to the manufacturer and parking damaged EVs that are equipped with lithium-ion batteries at least 50 feet from structures, other vehicles or any combustible materials. This is in part because a cracked battery cell can leak slowly and ignite at an unpredictable time.

After the headline-making fire in August in South Korea, officials there announced they would impose a rule capping charging of electric vehicles to 90 percent inside garages. It’s an effort to address one potential fire risk: overcharging.

As technology and design arrangements evolve rapidly, Ingram expects more businesses, insurance carriers and other stakeholders to engage in what he describes as “extrapolated engineering.”

“Fire protection specialists will draw from what is known about similar risk scenarios and then design protection systems that should control an evolving fire threat,” Ingram said. “However, until testing of the protection schemes in the actual environment intended for use is completed; the viability of the control is not 100%. It’s about identifying the exposures and managing them to the best of our ability. Protection is in everyone’s interest.”

1. Young, Jin Ju. “A Mercedes-Benz Fire Jolts South Korea’s E.V. Transition.” The New York Times. 27 August 2024. (Access may require a subscription.)

2. Hutchison, Victoria. “Research Insights: Fire Safety for Electric Vehicles and Other Modern Vehicles in Parking Structures.” National Fire Protection Association. 12 July 2024.

3. Hopkins, Terry. “Did you know? Fire sprinklers in open parking garages.” National Fire Sprinkler Association. 30 April 2024.

4. Ibid.