Fatal I-55 pileup crashes occur amid Louisiana 'superfog'

Dense fog advisories were lifted across portions of southern Louisiana on Tuesday morning, one day after deadly pileup collisions occurred along Interstate 55 amid a "superfog." At least eight people were killed and dozens more were injured after at least 160 vehicles collided along north and southbound lanes of the highway late Monday morning.

More than 25 people were transported to area hospitals with injuries ranging from critical to minor, according to the Louisiana State Police. Troopers responded to multiple crashes in both directions along I-55 between Ruddock and Manchac, Louisiana, and urged motorists to avoid the area if possible.

An eyewitness, Ka'Miyah L'Oreal Tymes, posted videos of the aftermath of a multiple-vehicle collision a bit farther to the north along I-55 in Ponchatoula, Louisiana. She described the chaotic scene and noted that vehicles were exploding.

A portion of the crash scene was fiery after the chain reaction, Louisiana State Police confirmed, adding that "one tanker truck carrying hazardous liquid" was being off-loaded due to the tank/trailer being compromised.

Louisiana Gov. Jon Bel Edwards issued a statement via X on Monday, cautioning motorists to be careful.

"The combination of wildfire smoke and dense fog is dangerous, and I want to encourage all Louisianans in affected areas to take extreme caution when traveling," he said.

"I also want to thank the first responders and medical personnel who have worked so diligently to save lives and render aid," Edwards said, adding that the best way to help police is to donate blood to replenish dwindling supplies.

Troopers worked to clear the remainder of vehicles from I-55 on Tuesday morning, but the highway will be closed until damage to the bridge has been assessed.

The National Weather Service (NWS) office in New Orleans explained in a post on X that dense fog and smoke "combined to form what is known as Superfog."

An area of high pressure in control across the region helped promote clear skies and calm winds, two critical ingredients for developing fog.

Dense fog led to reduced visibility of less than one-quarter of a mile early Tuesday morning across Louisiana parishes around Lake Pontchartrain and Maurepas, including New Orleans and metro Baton Rouge, according to the NWS. Advisories for dense fog were in effect until 10 a.m. CDT Tuesday.

Smoke from nearby marsh fires contributed to the dangerously low visibility. The region has been exceptionally dry this year, helping to fuel the fire weather. The area picked up only about half of the historical average precipitation or about 26 inches less than that historical average.

Increasing winds that developed later Tuesday morning caused some areas of fog to lift, but others still faced dangerous morning commutes.

"Fog is a possibility again early Wednesday and Thursday morning," AccuWeather Senior Meteorologist Tom Kines said, adding that the fog should be less widespread and not last as long as past mornings. "The wind should pick up early in the day, dispersing the fog quickly."