Super fog leads to tragic 158-vehicle pileup on Interstate 55 in Louisiana

Dense fog and smoke have combined to form what is known as super fog, heavily impacting Interstate 55 in Louisiana’s St. John the Baptist Parish on Monday morning, October 23, 2023, and leading to a massive vehicle pileup in which at least 7 people lost their lives and more than 25 were taken to hospitals with injuries ranging from minor to critical.

The event took place on the morning of October 23, 2023, and involved at least 158 vehicles, including a tanker truck carrying an undisclosed “hazardous liquid.” Authorities reported that some vehicles were ablaze following the initial collisions. The Louisiana Department of Traffic Development noted an 11 km (6.8 miles) backup on the highway.

“Preliminary investigation revealed that at least 158 vehicles were involved in the crash,” Louisiana State Police said. “That total is from both north and southbound lanes. Seven fatalities have been confirmed. Over 25 individuals were transported to area hospitals with varying degrees of injuries from critical to minor. Many victims sought medical assistance on their own.”

#UPDATE Louisiana State Police reports 7 people are now dead and at least 30 injured due to the massive pileup on I-55.

First responders say that number could climb as they continue monitoring the survivors of the crash. The wreck involved 150 vehicles

pic.twitter.com/N7wpzMZQAn

— Andrés Fuentes (@news_fuentes) October 24, 2023

Here’s a look a Jean Lafitte Blvd this morning as fog mixes with smoke from a nearby marsh fire.

Drive cautiously if you have to get through this area this morning. JPSO is escorting cars out of the fog.@FOX8NOLA pic.twitter.com/17kQbbfnms

— Andrés Fuentes (@news_fuentes) October 23, 2023

These images of multiple vehicles involved in crashes on I-55 and fires closing north and southbound travel were sent to us by Brad Denton, a motorist from Nashville, Tennessee. Authorities say there are two confirmed dead>>https://t.co/p2ctyyrKaS pic.twitter.com/6Bxo8TGr7u

— FOX 8 New Orleans (@FOX8NOLA) October 23, 2023

RAW VIDEO: Scene of multiple crashes and fires on I-55 northbound near the Manchac exit>>https://t.co/p2ctyyrKaS pic.twitter.com/eYJIPb7bw9

— FOX 8 New Orleans (@FOX8NOLA) October 23, 2023

A @FOX8NOLA viewer sends us video of what I-55 looks like this morning after multiple car wrecked killed two people.

Officials say there are about 25 crashes in the pileup on both north and southbound I-55.

The interstate is closed both ways at this time. pic.twitter.com/sD2qhepNlX

— Andrés Fuentes (@news_fuentes) October 23, 2023

pic.twitter.com/mCbbSx5IEE

— 🃏The Joker🃏 (@thejoker2543) October 23, 2023

State police worked into the evening to move the compromised tanker truck. “Once the tanker is removed, first responders will be able to better assess the vehicles in that immediate area. It is possible that additional fatalities could be located,” the police said. The pileup occurred on a 39 km (24 miles) stretch of Interstate 55 near New Orleans, which is expected to remain closed for an unspecified period.

Meteorological reports identified the hazardous weather condition as “super fog,” a combination of fog and smoke that can reduce visibility to less than 3 m (10 feet). This type of fog was a contributing factor to the accident and was prevalent in the area at the time of the pileup, according to the National Weather Service. Visibility levels were recorded below 0.4 km (0.25 miles) at a nearby weather station from 04:00 CDT to just before 10:00 CDT.

Dense fog & smoke have combined to form what is known as Superfog (yes, it is the technical name) & this is still heavily impacting I-55 between Ponchatoula & LaPlace. The interstate was still closed according to @La_DOTD due to multiple accidents. Fog is slowly improving. pic.twitter.com/xwovJBbuco

— NWS New Orleans (@NWSNewOrleans) October 23, 2023

The Hale Boggs Memorial Bridge towers above a foggy landscape. @MargaretOrr @flyneworleans pic.twitter.com/tnQu5YMoN4

— Paul Morse (@PaulMorsePhoto) October 23, 2023

Louisiana has been grappling with extreme weather conditions including wildfires, heat, and drought since the summer. Exceptional drought conditions are reported in 62% of the state. The city of New Orleans revealed that it is monitoring an active fire burning underground in forested wetlands between Bayou Sauvage National Urban Wildlife Refuge and the Michoud Canal.

State and local authorities have urged the public to exercise extreme caution while traveling and to report any missing family members who might have been in the affected area. Louisiana Governor John Bel Edwards encouraged blood donations to assist the medical personnel treating the injured.

Earlier reports from St. John the Baptist Parish Sheriff Mike Tregre indicated that three 18-wheel trucks collided in the northbound lanes and were fully engulfed in flames. In the southbound lanes, two separate multi-car pileups were reported, one of which also resulted in a fire. First responders had to reach the accident scenes on foot due to complete gridlock, complicating rescue efforts.

The National Weather Service in New Orleans said a dense fog advisory will be in effect overnight tonight into Tuesday morning, October 24 (LT) for parishes near Lakes Pontchartrain and Maurepas. Due to ongoing marsh fires in the area, the fog could be enhanced to produce near-zero visibility (super fog) conditions again.

Please take extra caution when traveling tomorrow morning, NWS said.

• Leave early and give yourself plenty of time to commute
• Use your LOW beam headlights
• Keep extra distance between other cars
• Delay travel until conditions improve if possible

A dense fog advisory will be in effect overnight tonight into tomorrow morning for parishes near Lakes Pontchartrain and Maurepas. Due to ongoing marsh fires in the area, the fog could be enhanced to become near zero visibility conditions known as superfog. pic.twitter.com/5w4v0lSVWp

— NWS New Orleans (@NWSNewOrleans) October 23, 2023

Super fog forms when a mixture of smoke and moisture released from damp smoldering organic material such as brush, leaves and trees, mixes with cooler, nearly saturated air. Under light wind conditions, super fog meanders through low terrain areas such as creek beds or drainage ditches. Super fog can be very dangerous when present over highways and has been the cause of several large, multi-vehicle pileups in the past.

References:

¹ 7 people killed after more than 150 vehicles crashed along Louisiana’s I-55 amid dense fog, officials say – CNN – October 23, 2023

² Louisiana ‘super fog’ pileup on interstate leaves 7 dead, 25 injured, over 150 vehicles damaged – Fox News – October 23, 2023

Featured image credit: Louisiana State Police