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.

WATCH: Hundreds of cars pile-up today in dense “super fog” on I-55, west of New Oreans

Dense fog and smoke from two marsh fires combined early Monday to create a "superfog" that blanketed I-55, causing a half-mile of deadly, chain-reaction crashes that shut down the highway in… pic.twitter.com/AbGPxudFry

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