Police say that wildfire smoke from marsh fires mixed with dense fog early on Tuesday morning in the Irish Bayou near New Orleans.
The superfog caused near-zero visibility for drivers on I-10, which saw multiple accidents and the death of a male motorist.
New Orleans Police Department said that multiple people were taken to the hospital and sections of I-10 were closed in both directions.
Conditions in the area had cleared up by 11am, according to the National Weather Service, which had warned motorists to stay off the roads.
On 23 October, seven motorists died and around two dozen were injured in a series of accidents involving 158 cars on I-55 near New Orleans.
Weather experts say that an extreme drought in the region, which is expected to last further into winter, is worsening wildfires that contribute to the superfogs.
“During the late night and early morning hours, a temperature inversion sets up near the ground and can trap in smoke from nearby fires,” said AccuWeather Senior Meteorologist Alex Sosnowski.
“When the air is humid enough, as it was Tuesday morning, the air cools and becomes saturated and allows fog to form at the same time that smoke is present.
“When both conditions are present like they were Tuesday morning, and a couple of weeks ago when a deadly pileup crash happened, super fog can develop.”