WATCH: ‘Superfog’ blamed for pile-up of 158 cars in New Orleans highway that killed at least 7

A “superfog” of smoke from marsh fires and heavy morning fog produced a string of collisions on Interstate 55 in New Orleans on Monday that left a long stretch of twisted and charred vehicles, trucks, and tractor-trailers. At least seven people were killed in the incident. The Louisiana State Police reported that 158 automobiles were involved and that 25 people were injured. However, they cautioned that the number of fatalities may rise as first responders searched for victims through the night with the lingering stench of burning debris.

Cars were burned, smashed, and stacked on top of one another. Some people got out of their vehicles and stood on the side of the road or on the roofs of their cars looking in disbelief at the disaster, while others cried out for help. Clarencia Patterson Reed was driving with her wife and niece and could see people waving their hands for her to stop, but when she did her car was hit from behind and on the side by two other vehicles, she told media.

“It was ‘Boom. Boom.’ All you kept hearing was crashing,” Reed said. She was able to scramble out of her car, but her wife was pinned inside and injured her leg and side. Another driver Christopher Coll, said he was already braking when a pickup truck “drove up on top of my work trailer and took me for a ride.” Coll could smell smoke as he heard the sounds of crashing cars and popping tires. He was able to kick open his passenger door to escape and then helped others — pulling out one person through a car window. While 25 people were transported to the hospital, with injuries ranging from minor to critical, others sought medical aid on their own, authorities said. Gov. John Bel Edwards asked for prayers “for those hurt and killed” on Monday and issued a call for blood donors to replenish dwindling supplies. Louisiana State Police shared aerial photos on their Facebook page showing the crashed cars and extensive debris on both northbound and southbound lanes of the elevated interstate, which passes over swamp and open water between lakes Pontchartrain and Maurepas. As of Monday afternoon, state troopers were still working “to notify families, investigate the exact causes of the crashes” and coordinate with the state’s transportation department to have the bridge inspected. Traffic backed up for miles in both directions on I-55. The lack of visibility also prompted closures of parts of I-10 and the 24-mile (39-kilometer) Lake Pontchartrain Causeway at times. School buses were summoned to transport stranded motorists from the accident sites. At midday, state police told reporters at the scene that one vehicle went over the highway guardrail and into the water, but the driver escaped unharmed. The National Weather Service said there were multiple wetland fires in the region. Smoke from the fires mixed with fog to create a “superfog.” Visibility improved as the fog lifted, according to the agency, but similarly dangerous conditions could occur in coming days. (with inputs from agencies)