7 people killed in crashes on Louisiana’s I-55: VIDEO

Updated: 24 OCT 23 10:50 ET

By Mary Gilbert and Macie Goldfarb, CNN

(CNN) — At least seven people were killed Monday in a slew of crashes along Interstate 55 in Louisiana’s St. John the Baptist Parish that involved at least 158 vehicles, state police say.

More than 25 people were taken to hospitals with injuries ranging from minor to critical, Louisiana State Police said in an evening news release. And many victims sought medical help on their own, authorities said.

Meteorologists earlier said “super fog” had heavily impacted the area, just west of New Orleans, around the time of the pileups. Super fog is a thick fog that develops in damp, smoky conditions and can send visibilities plummeting to less than 10 feet, according to the National Weather Service.

Some of the vehicles caught on fire after the initial crash, authorities said. One of the vehicles involved in the wrecks was a tanker truck carrying “hazardous liquid,” police said without elaborating on the substance.

Police were working Monday evening to move the truck due to a “compromised tank/trailer.”

“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,” state police added.

Authorities have asked the public to reach out if they have a missing family member who was traveling through the area Monday morning.

Louisiana Gov. John Bel Edwards said he was praying for those killed and wounded in the crashes.

“The combination of wildfire smoke and dense fog is dangerous, and I want to encourage all Louisianans in affected areas to take extreme caution while traveling,” Edwards said on X, formerly known as Twitter.

“I also want to thank the first responders and medical personnel who have worked so diligently to save lives and render aid,” the governor added. “The best way you can help them, besides exercising caution on the road, is to donate blood at your local blood donation center. It will help replenish supplies that are being drained today to care for the wounded.”

Earlier, St. John the Baptist Parish Sheriff Mike Tregre told CNN affiliate WVUE about three 18-wheel trucks collided in the northbound lanes and were fully engulfed in flames. In the southbound lanes, there were two reported multi-car pileups, one of which was also producing flames.

According to Tregre, all first responders had to be on foot because the crashes left the area “completely gridlocked.”

“The situation is pretty bad,” he added.

Visibility levels were below a quarter mile at a nearby weather station from just after 4 a.m. CDT until just before 10 a.m. CDT. Visibility likely neared zero at times throughout the morning when the fog was at its densest.

The incredibly dense fog, known as “super fog,” was caused by fog combining with smoke from nearby fires.

Louisiana has battled unprecedented wildfires, extreme heat and relentless drought since the summer. Exceptional drought, the highest category tracked by the US Drought Monitor, is in place across 62% of the state.

In a statement Monday, the city of New Orleans said it is monitoring an active fire burning underground in forested wetlands between Bayou Sauvage National Urban Wildlife Refuge and the Michoud Canal.

The lack of rain combined with the summer’s extreme heat dried out wetlands and reduced the water table’s depth, the city said. The blaze being monitored has been burning at and below surface level, it added.

A repeat of Monday’s super fog is unlikely for Tuesday morning as “winds should be much stronger,” the National Weather Service in New Orleans said Monday on X, previously known as Twitter. Winds need to be calm or very light in order for dense fog to form.

Patchy areas of dense fog may be possible but will not be as widespread as Monday, the city said, citing the weather service.