A thick “super fog” rolled over New Orleans on Monday, enveloping the area in an impenetrable fog that caused a traffic jam involving dozens of vehicles and left at least seven people dead, authorities said.
At least 158 vehicles were involved in the series of crashes, which began shortly before 9 a.m. on Interstate 55 northwest of New Orleans, Louisiana State Police said, noting that fog was a “contributing factor.” Another 25 people were injured, some of them in serious condition, the police said.
After the accidents, which involved vehicles in the northbound and southbound lanes, some vehicles caught fire, according to police. The tanker truck carrying the “dangerous liquid” is being removed, police said, adding that it is possible “additional deaths may be located.” The state police urged all those who have a missing family member to contact the agency.
Aerial images posted on the State Police Facebook page several hoardings on Interstate 55, including some cars and trucks that appeared to be charred.
The thick fog was created by a combination of moisture in the air and smoke from sporadic wildfires across the Mississippi River Valley toward Baton Rouge, La., said Tyler Stanfield, a meteorologist with the National Weather Service in New Orleans.
“It was a perfect storm,” Mr. Stanfield said.
Although super fog is uncommon, it is not an unheard of phenomenon. New Orleans typically experiences super fog twice a year. It is usually fueled by swamp fires, which have become more common in the area this year due to drier conditions, Mr Stanfield said.
The fog began to descend around 3 a.m. Monday and became thick around sunrise, he said. Visibility for drivers was only one-eighth of a mile.
State police portions of Interstates 10, 55 and 310 closed on Monday morning and warned that, due to heavy fog, “drivers should avoid the area if possible and use alternate routes.” Interstate 10 and 310 South later reopened, but portions of Interstate 55 remained closed Monday night.
By afternoon, most of the fog had dissipated, with the last of it lingering in the suburbs west of New Orleans, Mr. Stanfield said.