7 killed in 158-vehicle pileup as ‘super fog’ clouds New Orleans

A pileup involving at least 158 vehicles on Interstate 55 in Louisiana killed seven people and sent more than 25 to the hospital Monday morning, state police said. The National Weather Service in New Orleans said the area had been affected by a “super fog,” created by smoke from wildfires mixing with dense fog.

State police said rescuers were continuing to search the crash site, located in an area called St. John the Baptist Parish, and that it’s possible the death toll would rise. Part of the scene caught fire shortly after the initial accident, and one large truck carrying a hazardous liquid was being offloaded because of a compromised tank or trailer, police added. Images taken after the event Monday showed scorched, mangled cars piled on top of one another.

Louisiana Gov. John Bel Edwards (D) called for prayers and encouraged residents in affected areas to take “extreme caution when traveling” and to donate blood. Rep. Troy Carter (D-La.) said he was “devastated” to learn of the incident, describing it as “truly heartbreaking.”

Super fog conditions form when smoke and moisture released from damp smoldering material - such as brush, leaves or trees - mixes with cooler, almost saturated air. It can reduce visibility to less than 10 feet, and “can be very dangerous when present over highways,” according to the NWS, which added that the phenomenon “has been the cause of several large, multivehicle pileups.”

Schools in the areas around the crash announced a delayed opening Tuesday, citing the fog. On Monday evening, the NWS had released a statement warning of dense fog conditions on roads Tuesday morning, which it had said could worsen to “near zero visibility conditions known as superfog.”

At the time, the NWS advised drivers to leave early, drive slowly, use low-beam headlights and keep extra distance between vehicles - or even delay travel, if possible.