Unbelievably dramatic and tragic scenes have unfolded in New Orleans, Louisiana, as a result of a rare meteorological phenomenon called super fog.

At least eight people are dead with more than 60 injured after more than 160 vehicles were trapped in a fiery pileup on an elevated section of the I-55 highway.

At least 150 vehicles collided on 1-55 outside of New Orleans Monday morning amid a "superfog." At least 7 people were killed, and more than 2 dozen were injured.

Smoke from nearby marsh fires contributed to the dangerously low visibility. pic.twitter.com/XPqlmReDtv

— AccuWeather (@accuweather) October 24, 2023

The massive crash was caused by low visibility, which as stated was caused by super fog.

What is super fog?

In simple terms, super fog is a combination of wildfire smoke and natural fog.

NEW ORLEANS (AP) — Officials say at least 7 killed in massive vehicle crashes in Louisiana due to 'Superfog.'pic.twitter.com/W3n6hdiYM0

— philip lewis (@Phil_Lewis_) October 24, 2023

Normally in Australia, we don't see the two events happening together as fog often forms when it's cool and still, while fires are fanned by strong winds as every Aussie knows.

But in the marshy land around New Orleans – a city which sits on low-lying land near the Mississippi River's junction with the Gulf of Mexico – marsh fires occur late in summer and early autumn and can burn out of control even in relatively still conditions.

This camera in New Orleans captured the blinding fog that led to significant accidents on I-55 in Louisiana today: pic.twitter.com/SKwhqwzkdN

— The Weather Channel (@weatherchannel) October 23, 2023

America's National Weather Service defines super fog as:

"A mixture of smoke and moisture released from damp smouldering organic material such as brush, leaves and trees, mixes with cooler, nearly saturated air. Visibility is lowered to less than 10 feet [three metres]. Under light wind conditions, super fog meanders through low terrain areas such as creek beds or drainage ditches. Super fog can be very dangerous when present over highways, and has been the cause of several large, multi-vehicle pileups."

That last line about multi-vehicle pile-ups is one forecast which America's National Weather Service sadly got very right.