Author(s): Jesse Roman. Published on March 1, 2019.

Ramp Risk

Modern vehicles present a greater fire hazard than ever before. To address that risk, experts are taking a new look at the design and safety elements of parking garages, common features of urban landscapes around the world


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LIKE COUNTLESS OTHER former industrial centers, the docks along the River Mersey in Liverpool, England, have undergone a dramatic transformation in recent decades. Where blue-collar workers once toiled amid gritty smokestacks, schlepping ship cargo to and from red-brick warehouses, today’s waterfront bustles with tourists and well-to-do locals, drawn to a growing roster of trendy restaurants, entertainment venues, and luxury hotels.

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Read the after-incident report on the King's Dock car park fire from Merseyside Fire & Rescue

King’s Dock, perhaps the most touristy of the city’s gentrified waterfront neighborhoods, was abuzz with visitors in the late afternoon of New Year’s Eve 2017. In addition to the usual activity in anticipation of the night’s revelry, thousands had come to King’s Dock that evening to attend the popular Liverpool International Horse Show, held at the 11,000-seat Echo Arena in the heart of the neighborhood. By 4:30 p.m., nearly all of the spaces at the multi-story King’s Dock car park, located next to the arena, were filled with vehicles, many of them the large trucks and SUVs preferred by the equine crowd.

Sue Wright and her husband Mark were in one of the last vehicles to enter the packed garage that night. As the couple got out of their car and headed toward the exit, they had no way of knowing that neither they nor hundreds of other people would ever see their vehicles intact again.

According to an after-incident report compiled by the Merseyside Fire & Rescue Department, the first sign of trouble came at precisely 4:29 p.m., when a closed-caption television camera captured smoke rising from a Land Rover parked on the third floor. By the time the Wrights walked past it, about 10 minutes later, “flames were just shooting out of the engine and coming past the tires,” Susan Wright told the BBC. “It looked like a ball of fire on the front of the car and it was producing a lot of smoke.”

Merseyside Fire & Rescue was alerted of the situation at 4:42 p.m. and were on the scene eight minutes later. By the time the fire crews dragged hose lines to the third floor, about 18 to 20 vehicles were fully involved. The vehicles burned so hot that the three hose lines the department typically deploys to such incidents weren’t nearly enough to suppress the fire, explained Merseyside Group Manager Barry Moore in an interview with NFPA Journal in January.

“If the heat absorption of the water can overcome the heat output of the fire, we will put that fire out—if it cannot, we will forever chase that fire, and that’s where we were at that night,” he said. “With the fuel load of these modern vehicles and the size of the vehicles in the garage that night, the fire just kept growing and growing and we could not match that growth. It went beyond our extinguishing capability.”

Merseyside firefighters surrounded and battled the blaze for nearly an hour, continuously adding resources to the fight, but they could never gain the upper hand. As temperatures exceeded 2,000 degrees F in the vicinity of the fire, the tires on burning vehicles began to explode. Plastic fuel tanks—now standard on about 80 percent of vehicles—melted and ruptured, sending burning gasoline pouring onto the concrete floors, which began to disintegrate from the intense heat.

Like many garages, the King’s Dock car park was equipped with drainage on each floor to catch excess surface water and carry it out of the garage. A 15-millimeter-wide slot ran the length of the garage floor beneath rows of parked cars; water that seeped into this slot was caught by an aluminum gutter below and carried outside. About two hours into the fire, the gutter melted away, allowing the burning gasoline to rain down freely through the drainage slot onto vehicles parked on the floor below. Meanwhile, the slot on the floor overhead acted as a vent that carried super-heated gas and smoke to the vehicles above. Within minutes, dozens of cars and trucks above and below the firefighters were engulfed in flames, and the decision was made to pull the firefighters out of the building, which was at risk of structural collapse. “Within 10 or 15 minutes after we withdrew, there was a very large escalation of the fire and the whole of the car park was involved,” Moore said.

As the fire raged, buildings in the surrounding area were evacuated, and firefighters turned their focus from extinguishment to containment. Finally, by 7:45 a.m. on January 2, nearly 40 hours after Merseyside firefighters arrived on the scene, the fire had burnt itself out. By then, the garage was little more than a hunk of charred concrete, entombing the twisted remains of nearly 1,200 cars, trucks, and SUVs. Remarkably, no one was killed or injured in the fire.

As word of what had happened at King’s Dock spread, fire protection engineers and researchers across the world were stunned by the magnitude of the event.

“It was dramatic to the point that everyone began immediately asking, ‘What happened here? Every single car in an eight-story open-air garage burned? How is that possible?”’ said Casey Grant, executive director of the Fire Protection Research Foundation. “From a fire protection engineering standpoint, it was almost like Grenfell. People began asking all sorts of critical questions.”

Exterior of the King's Dock parking lot after the fire

Interior of the King's Dock parking lot after the fire.

'How is that possible?' The exterior of the King's Dock car park, top, following the fire that destroyed the entire structure. Below, the facility included design and construction features that allowed the fire to spread and made containment impossible for the local fire service. Photographs: Merseyside Fire & Rescue

Grant wasn’t the only one to make a comparison to the Grenfell Tower fire, the residential high-rise fire in London that killed 72 people in June 2017. Even though no lives were lost at King’s Dock, the incident “is being seen and treated by us as something a lot like Grenfell—a precursor to what could be a much more catastrophic incident,” Moore said. “If this fire had ignited just a half hour later, we would have had 600-plus cars queuing to get out of this building, because an event was just finishing. We think it is our responsibility to share what we learned from this event as far and as wide as possible.”

The Plastic Revolution

Since King’s Dock was spared the fatal outcome of Grenfell, worldwide media attention has been limited, and corresponding public outrage has been muted. But the incident delivered a serious jolt to the fire protection community—researchers, code developers, fire officials, and others see King’s Dock as a bellwether event, and perhaps as a seminal moment for parking garage fire protection.

A key concern, experts say, is whether the current fire protection guidance for parking garages is still adequate considering how dramatically vehicles have changed in recent decades. There is also growing concern about how to protect newer design and layout trends in urban garages.

“Many of us in the fire protection and suppression fields, including myself, are asking, ‘Do we possess all of the necessary information?’” said Michael Carsillo, chair of the Garages and Parking Structures Committee that oversees NFPA 88A, Standard for Parking Structures. “Advances in automotive technology are very real and rapidly evolving. There are gaps in our understanding of how changes in automotive design and construction impact fire characteristics and fire growth.”

In the aftermath of King’s Dock, Grant said he had numerous conversations with concerned engineers who approached him independently to discuss the need for more research into parking structures and the fire characteristics of modern vehicles. He agrees that a project is critical. “We just went through our list of research projects for 2019, and this issue is our number-one priority,” he said. “When you put a sprinkler system in a parking garage, you obviously want to be sure it’s going to control a fire—you don’t want to wonder and hope. Before we build 10,000 more garages around the world, we need to be sure.”

The specific project details depend on sponsors and the resources available, Grant said, but the primary goal will be to quantify the fire hazards inherent in modern vehicles and determine the optimal design and fire protection schemes for garages to combat them. Findings from the project will likely impact at least two NFPA documents, NFPA 13, Standard for the Installation of Sprinkler Systems, as well as NFPA 88A.

Underpinning this issue is the fact that the materials used in the constructions of almost all vehicles have changed dramatically over the decades. Car companies, under pressure to meet government-mandated fuel-efficiency and safety minimums, have methodically swapped out metal parts for new durable plastics to make vehicles lighter, safer, more rust-resistant, and less expensive. Vehicles also contain more electronics and plastic wiring than they used to, adding potential ignition sources.

“The transition began in the 1960s on the vehicle interior, as softer materials and padded dashboards were desired over steel dash panels for crash protection,” said Dan Madrzykowski, a longtime researcher with the National Institute of Standards and Technology (NIST) who now works at the UL Firefighter Safety Research Institute. “In the 1970s, cars began to lose their steel bumpers, which were replaced by urethane bumper covers. As the need for better gas mileage and improved corrosion resistance grew, sheet metal was replaced with plastic or fiberglass. Today, even engine components that were traditionally made of cast iron or aluminum, such as the intake manifold, are now made from high-temperature plastics.”

Those changes mean that modern vehicles can present a greater fire hazard than older vehicles, an evolution that parallels the fire problem in modern homes. In the 1950s, homes were typically built with slow-burning solid wood beams and filled with materials like hardwood furniture and natural fabrics. Modern homes, by contrast, are now typically constructed with faster-burning lightweight wood materials and furnished with particleboard furniture, polyethylene foams, and loaded with highly combustible plastics. Scientific testing, along with anecdotal evidence from firefighters and fire safety advocates, demonstrates that fires in residential structures today burn faster and more ferociously than they did a generation ago.

A similar trend appears to have emerged in the automotive industry. According to the American Chemistry Council, modern vehicles are now composed of about 50 percent plastic by volume, even though plastics account for only 10 percent of the average vehicle’s weight. Industry experts believe that as better technologies and additional fuel-efficiency mandates kick in, the percentage of plastics in cars will only increase. In the United States, for example, the Corporate Average Fuel Efficiency standards mandate that carmakers’ passenger vehicle fleets average 54.5 miles per gallon by 2025. To meet those and similar European requirements, the average car will incorporate nearly 350 kilograms of plastics by 2020, up from 200 kilograms in 2014, according to an analysis by IHS Chemical, a chemical industry research group.

With no definitive worldwide aggregation of parking garage fires, it is hard to quantify how the move toward more plastics in vehicles has changed the frequency or intensity of garage fires, but many experts believe the anecdotal evidence is striking. In addition to King’s Dock, numerous recent garage fires involving dozens and even hundreds of vehicles have made headlines in just the past few years (see a partial list of those incidents above). To see statistics from vehicle storage and garage fires in the US from 2012 to 2016, use NFPA’s new interactive tool “Fires by Occupancy or Property Type” at

For hard evidence, perhaps the best study on how parking garage fires have evolved comes from a report authored in 2015 by four French researchers. The researchers looked at data gathered from a survey of several hundred French parking garage fires between 1995 and 1997, and analyzed them against a survey of French garage fires that occurred between 2010 and 2014. The conclusion: “Fire hazards in car parks (have) increased a lot in 20 years with the evolution of activities and the new car technologies,” the authors wrote.

The data suggests that a typical garage fire today is much more likely to involve multiple vehicles than two decades ago, hinting that fires are in fact burning with more severity. In garage fires between 1995 and 1997, 98 percent involved fewer than four vehicles; only 1 percent of fires involved more than five vehicles, and none of the fires reviewed involved more than seven vehicles. By contrast, 8 percent of the garage fires between 2010 and 2014 involved more than five vehicles, and 6 percent involved more than seven vehicles.

Infographic on the increased amount of plastics in modern vehicles

Modern garage fires also appear to be much harder to extinguish, the data revealed. In 1997, 95 percent of garage fires analyzed were extinguished in under 60 minutes. However, in French garage fires occurring between 2010 and 2014, only 40 percent were extinguished in under an hour; 30 percent of the fires took more than two hours to extinguish, and 10 percent took more than four hours. By contrast, fewer than 1 percent the 1997 fires took longer than two hours to put out.

'Fact-Finding Mode'

While much evidence supports the idea that vehicle fires are more hazardous than in previous eras, debate on what to do about the problem is just beginning. Ultimately, more research is needed to provide code and standard developers with clear options.

An important finding in the King’s Dock fire, Moore said, was that nothing about the garage was amiss—two previous inspections revealed that everything was legal and fully compliant with all building regulations. “That is a very strong message—there were no issues with the building construction of this car park. It was well kept and clean, and yet this happened,” he said. “There’s no reason to think that the next car park won’t be the same. This type of fire could happen in any city in the world at any time.”

Across the world, few parking garages outside of the United States are required by building codes to install sprinkler protection. In the United Kingdom, parking structures must comply with Approved Document B, a building code crafted in 1968, which does not require sprinklers because its authors concluded that “fire spread from one vehicle to others would not occur and that if it did, the Metropolitan Brigades would invariably be in attendance within three to four minutes,” the Merseyside report said. Concerned that this guidance may be outdated, in 2010 the government published results from “Fire Spread in Car Parks,” a three-year project it commissioned that concluded, among other things, that sprinklers are effective in both controlling developing and fully developed fires. Despite that observation, no sprinkler requirement was ever added to Approved Document B. In the months after King’s Dock, Merseyside officials have said that if sprinklers had been installed at the car park when it was built in 2007, the fire would not have spread like it did. Meanwhile, the problem grows worse with each passing year.

“It’s been nearly 10 years since that study, and the difference between a vehicle bought in 2009 and 2019 is considerable, even in that very short window,” Moore said, alluding to the added plastics and combustibles in modern vehicles. “We in the UK are still building to regulations set in 1968, and when you look across our region, all the car parks are exactly the same. They are all compliant, but the vehicles have moved on. You could argue that the building regulations haven’t.”

In the United States, NFPA 88A is the most widely used standard for parking structures. Generally speaking, the document does not require sprinklers in parking structures that are considered to be open—meaning they have a minimum amount of natural ventilation on at least two sides. Underground parking garages, or those wrapped or covered on three or more sides, are considered closed garages and require sprinkler protection.

Without blueprints, it’s hard to say whether King’s Dock garage would have been considered open or closed and thereby subjected to the sprinkler requirement under NFPA 88A, said Kevin Carr, the NFPA staff liaison who works on the document. Nonetheless, he said that the Liverpool incident has “opened up the debate” and generated questions among technical committee members and code officials about whether the overall requirements, including sprinkler requirements, in NFPA 88A are sufficient.

“We are in fact-finding mode right now,” he said. “The Liverpool event has really made people stop and ask questions about the causes, related issues, and how we can get some more data to make the correct and necessary additions to the code.”

In the current edition of the standard, which came out this year, the NFPA 88A committee added information to better define whether a garage is considered open or not. It also added guidance for garages that house autonomous vehicles, alternative fuel vehicles, and electronic charging stations, “in recognition that technology in the automotive world is changing and these garages will be the recipients of that technology,” Carr said.

As meetings on the 2023 edition of the standard get underway, adding a sprinkler requirement to open garages will likely be up for debate, but would require a lot of thought and additional information, Carr said.

Wes Baker, a chief engineer at FM Global and a member of the NFPA 13 technical committee, said that after the Liverpool fire, fire protection requirements in parking garages deserve another look. “When you look at the amount of plastics in cars now, both on the interior and the exterior, it should no longer surprise anyone when we see a fire like this,” he said of King’s Dock. “If that fire had occurred 30 years ago it would have been a single car, but not anymore.”

NFPA 13 classifies a parking garage as an “Ordinary Hazard, Group I” occupancy, defined as a space “with moderate quantity and low combustibility of contents.” Occupancies with that type of classification require sprinkler protection densities “designed for something where you have a fire, but it’s not a very big one,” Baker said. “With the higher amounts of plastics, I would certainly suggest the 13 committee should be looking more in the ‘Extra Hazard’ category for these, as opposed to the ‘Ordinary Hazard’ category. Right now, we are probably underestimating it.”

Since the King’s Dock fire, Barry Moore and his colleagues at Merseyside Fire & Rescue would agree that vehicle fires have been have undersold and overlooked for too long. They are working to spread that message at fire protection conferences across Europe and recently the United States. Moore calls the events at King’s Dock “the perfect storm,” but also “a very good case study.”

At his presentations, he said he wants to leave audiences with two clear messages, the first being that the risks and hazards of car park fires have changed, so arrive quickly with lots of resources. “You don’t want to be turning up under-resourced if you face what we faced,” he says. The other message—and one that Merseyside has also stressed to the British government as it reviews Approved Document B in the wake of Grenfell—is that fire sprinklers should be required at all parking structures.

“When you get this perfect storm, sprinklers won’t put the fire out but they might contain it long enough to allow firefighters to extinguish it in the early stages versus letting it spread uncontrollably,” he said. “When the fire does start to spread and the heat gets into the vents and the fuel starts running, that’s when it will get away from you very quickly. If that aligns with a busy period and you have people trying to get out of the car park, what happens then?”

JESSE ROMAN is associate editor for NFPA Journal. Top Photograph: Getty Images