THE DEADLY PILEUP ON INTERSTATE 55 stemmed from Louisiana’s historic drought. 

The immediate cause of Monday’s 168-car collision was “superfog,” formed when thick smoke from smoldering marsh fires mixed with moist fog, the kind that hugs the ground on cool, still Louisiana mornings. Drivers collided, faced with white-out conditions with zero visibility. At press time, the death toll stood at seven. The 22-mile Manchac Swamp Bridge on I-55 also remained impassable. 

The smoke feeding Monday’s superfog came from a fire burning on private land in New Orleans East, between Bayou Sauvage Urban National Wildlife Refuge and the Michoud Canal. 

At the root of all this damage is a historic drought that hit hard in southeast Louisiana, drying up an area typically known for its humid air, heavy precipitation and thousands of acres of watery swampland.

The region has experienced marsh fires before. In 2011, then-Mayor Mitch Landrieu called in the Louisiana National Guard to drop water on a stubborn 2,300-acre fire in a New Orleans East swamp that reportedly sent smoke as far away as Baton Rouge. 

But the conditions leading to multiple fires in late October are dire. Most of southern Louisiana is experiencing what the U.S. Drought Monitor describes as “exceptional drought” conditions, the most intense level of drought. 

The drought is impacting the entire Mississippi Basin, leaving the river with critically low water and a current too weak to keep saltwater from the Gulf of Mexico from creeping up the river to Plaquemines Parish. 

Locally, drought conditions exacerbated the fire in Orleans and another large marsh fire in Jefferson Parish. Most of Orleans Parish is suffering from “extreme drought,” one level below exceptional drought. But conditions are still arid enough to cause saltwater intrusion, crawfish die-off, crop-irrigation problems, poor air quality and difficult-to-extinguish fires. 

“What’s burning now is normally very wet, you would not see any fire there,” said Meredith Hardy, a spokesperson for the National Park Service’s fire response in Jefferson Parish, who described the drought as “unprecedented.”

THE SWAMP IN NEW ORLEANS EAST has been burning for at least 12 days. It’s in a wetland area “completely inaccessible” to the New Orleans Fire Department, according to Capt. Edwin Holmes, who said that it’s “on a large piece of private property, a wetland, that would be completely underwater, if it had rained at all.” The land is owned by Harvey Canal Holdings II LLC, according to Orleans Parish Assessor’s Office records.

The remote location makes it nearly impossible to accurately track the fire’s perimeter. But the U.S. Air Quality Index AirNow Fire & Smoke Map shows the fire as affecting 200 acres of swamp. 

The threat it poses to the nearby Bayou Sauvage Urban National Wildlife Refuge is moderate but not imminent, said Pon Dixson, refuge manager. At this time, smoke coming from the fire is the greatest concern, he said.

Still, being a federal nature preserve has its advantages when fires ignite, as Jefferson Parish officials discovered when fires began moving through 147 acres of wetlands within the Barataria Preserve, part of the Jean Lafitte National Historical Park and Preserve. The blaze has now been partially tamped down by inter-agency fire teams – crews from Jefferson Parish along with teams from seven states and four federal agencies, including the National Park Service, who worked to bring the fire to 52% containment.

The Lafitte conflagration was discovered about a week ago, on Tuesday, Oct. 17. Afterward, heavy smoke and fog rolled across lower Jefferson Parish, causing a loss of visibility for drivers and forcing school closures due to poor air quality. Two minor traffic accidents resulted from Jefferson’s superfog, with no injuries, according to Don Robertson, chief of fire services for Jefferson Parish. Since then, firefighting efforts there have markedly reduced the smoke from Lafitte, he said.

New Orleans East residents observed heavy smoke with a more chemical odor, once fire took hold in swampland there, dating back to roughly the same time, Tuesday, Oct. 17. 

The smoke intensified in Orleans on Sunday evening, and spread, until it was noticeable to visitors in the French Quarter and residents across much of the city. Overnight, into Monday morning, dense fog combined with the smoke, leading to the dangerous driving conditions that caused Monday’s massive, deadly highway collision, which made national and even world headlines because of its widespread wreckage.

Weather-wise, no relief is expected this week, though slightly stronger winds are expected to keep the superfog away until at least the weekend, according to forecasters with the National Weather Service. 

Still, if the wind subsides, a dome of high pressure will remain across the Gulf South through Monday, creating conditions favorable for seasonal fog, as the pressure pushes cooler air toward the ground that becomes saturated with water vapor. 

Unfortunately, rainfall is not expected to fall during that time, according to the National Weather Service New Orleans. “If we could get rain, we’d solve a lot of problems,” Robertson said.

Looking ahead, however, drought conditions should improve in the lower Mississippi Valley and Gulf Coast. A winter forecast released by the National Oceanic and Atmospheric Administration’s Climate Prediction Center shows a wetter-than-average forecast.

Putting out the peat

MARSH FIRES ARE FUELED BY PEAT – partially decomposed plant material that makes up the dense, spongy soil in some wetlands. 

When dried, peat is a potent fuel source; it’s cut into bricks and burned like firewood or coal to heat  homes in Ireland and Finland. Damp, still decomposing peat is causing the chemical smell and the thick smoke hanging above New Orleans East.

Peat does not burn cleanly. As it smolders, it releases a lasting haze of mercury and other toxic chemicals into the air, along with increased air pollution, in the form of small particulate matter. That has been reflected over the past week in New Orleans air monitoring, which has shown moderate levels of particle pollution. 

New Orleans health experts are advising people with existing vulnerabilities, such as lung or heart conditions, to reduce their activity level or shorten the amount of time spent outdoors. For those who need to be outside, the city is distributing masks to help limit inhalation of particulates.

Peat is most often found in land with high water tables, like the swamps of southeast Louisiana. Late last week, the Sewerage & Water Board began working with the Louisiana Department of Wildlife and Fisheries to pump water from a nearby drainage canal into the burning New Orleans East swamp, with hopes of flooding the area and putting out the peat fire. Wildlife and Fisheries staff have been moving the SWB pumps to inundate new areas, as needed. Together, the two pumps, a 12-inch and 8-inch pump, are pumping 96,000 gallons an hour, for 12 hours a day – enough to fill nearly two Olympic-size pools each day.

So far, the added water has not saturated the dry ground enough to snuff out all the flames. But it is helping to prevent spread: on Wednesday, when winds kicked up a new patch of fire, it was isolated by the new water, introduced from the canal nearest to SWB’s Drainage Pumping Station 15. 

Extended drought can cause peat-heavy wetlands to dry so severely that peat fires can burn deep underground, out of the reach of firefighters’ hoses. Dixson, the refuge manager, said that wildlife has likely moved from the affected area, waiting to return and forage. For instance, the birds will return to eat the charred insects, he said.  

In Lafitte, along with the influx of inter-agency firefighters, efforts got a high-tech boost from the National Park Service, which used infrared technology to identify hot spots underground and deployed helicopters and airplanes to drop water on the marsh fire. 

Then the inter-agency ground crews stepped in, to move through the marsh, using rakes, shovels and portable pumps to extinguish spot fires, which pop up from the heat retained by the peat underground. At night, they’ll use sprinklers to saturate targeted areas. The Park Service has also ordered additional crews from across the country to help.

Robertson, of Jefferson Parish Fire, has been a firefighter in Louisiana for 50 years. But – until this year’s drought – he’s never needed National Park Service crews fighting fire from the skies, he said. “I’ve never seen a plane drop water, except for on TV.”