Forensic Files - Season 2, Episode 3 - Killer Fog - (In HD) | Forensic Files

I felt like I was in a war zone with the explosions, the smell of smoke, uh the smell of burning flesh, people
screaming. >> It was the single most deadly automobile accident in American history. 99
vehicles, most of them destroyed. 12 people died. >> Identifiable more than 50 were injured.
>> Total destruction. >> If I hadn't been there and and I witnessed it, I don't believe I could
have believed. >> The accident happened along a three-mile stretch of highway long known for dense,
thick fog. But what was causing the fog? The victims and their families wanted answers.
[Music] [Music] [Applause] The accident occurred on Interstate 75 in Tennessee on a portion of highway
between Chattanooga and Knoxville. The highway was constructed through a valley which lies between the Cumberland
and Great Smoky Mountains. From the time the highway first opened back in 1973, there had been numerous multi-vehicle
chain reaction accidents in the same three-mile section. The first occurred just 4 months after
the highway opened. Three people died in a 17c car pileup. 10 were injured. Just one month later, there was a
ninecar accident. Although there were no deaths, nine were injured. During the first 6 years the highway was
open, there was an average of one multi-car accident each year. One of the largest was in November of
1978, involving more than 60 vehicles. Six people were killed. nearly 100 injured.
All of the accidents had one thing in common, the sudden appearance of a dense, thick fog, reducing visibility to
near zero. Tennessee State Highway officials responded by installing fog warning lights to warn drivers when fog
was in the area. Highway patrol officers were posted to stand watch every morning
along the fogprone area to make sure drivers slowed down when the fog warning lights were activated.
The combination of these two systems worked. For 11 years, there were no major accidents along the fog-prone
stretch of Interstate 75. But all of that changed on December 11th, 1990. >> It's a massive wreck. Everybody's
bumping into everybody. >> I've had several reports I've had an explosion in that area, and they're
still piling up. As I rolled down the window, I could hear the cars just crashing into each other one after
another. >> A motor home hit the front end of my truck after just seconds after I had
gotten out. And then vehicle started hitting the back of it. I'll never forget hearing one. He hit other cars
and just knocked them out of the way like there were nothing and came and crashed just to the right of that motor
home. The explosion was such that it almost knocked me down. Mike Curtis pulled this 14-year-old boy
out of the motor home, then rescued the boy's mother. >> And I turned and went back to get her
husband. All I could see was fire. I could smell hair burning. His coat came off burning in my hands.
[Music] It's probably the hardest thing I've ever had to witness. The most helpless feeling I've ever had.
[Music] The man burned to death. 12 people were killed, 56 others injured, making it the largest vehicular
accident in American history. These pictures were taken shortly after the accident when most of the fog had
dissipated. The vehicles that I saw, I don't even know if you could classify them as vehicles. What normally was a
pickup truck was 3 foot in length, body still in it. >> After 11 years without a serious
accident, the killer fog had struck again. But why? The families of the dead and
injured demanded answers. They wanted to know what caused the dense thick fog on
December 11th, 1990. [Music] On December 11th, 1990, 30-year-old Craig Piper was driving his
tractor trailer south on Interstate 75 on his way to visit his mother for the holidays.
[Music] When he entered the thick, dense fog, visibility was near zero. Within seconds, he crashed.
[Music] The flames were extremely intense and I knew there wasn't any way I could get
him out. And I had to stand there and watch this man burn uh in his vehicle. There wasn't really anything I could do.
Flames were too big. I didn't have a fire extinguisher. I just had to stand there and watch this this this man burn
alive. >> Craig Piper's mother wanted answers and hired attorney Doug Fees, who was not
only a lawyer, but also an engineer. She wanted Feast to find out what caused the
terrible fog that was responsible for her son's death. >> She said the the two people in that car
were killed and that her son had been burned alive in his tractor trailer and was wondering if there was anything that
I could do to help her. The accident occurred along Interstate 75 at its lowest point in the valley
about a half mile from where the interstate crosses the Hawaias River. Because of its location, fog has always
been common in this area. Fog is basically a cloud which forms on the ground. Fog occurs when there is too
much water in the air for the atmosphere to absorb. Since cooler air holds less moisture than warm air and cool air
gathers in lowlying areas, the valley through which Interstate 75 passes is perfect for the formation of natural
fog. But the fog described by the accident victims was extremely thick and dense.
Was the fog on the day of the accident naturally produced or was it caused by one or more of the local industries
nearby? >> On those three days there there was some amount of river fog uh although it was
relatively small. Uh on all three days there was a very noticeable uh emission of fog related uh water vapor uh from
the uh from the Bowwater facility. The Bowwater Paper Company is located 3 miles to the east of the Interstate
Highway. It is the largest producer of newsprint in North America and releases large quantities of water vapor into the
atmosphere 24 hours a day as part of the manufacturing process. Wayne Davis recommended that the state of Tennessee
conduct a more detailed study in order to understand the cause of the fogging conditions. The state decided not to
fund a more detailed study, but elected to install a fog warning system along the highway and posted state troopers to
patrol the fog-prone stretch of highway each and every morning. For 11 years, the system worked. Between 1979 and
1990, there were no serious multi-vehicle accidents along the 3m stretch of Interstate 75. The system
worked until December 11th, 1990. The Wayne Davis study was an important starting point for Doug Fees. But the
Davis study was conducted 12 years earlier. Fees needed to know what caused the fog on December 11th, 1990.
>> Doug Fees heard about a scientist who was using computers to track weather conditions and pollutants.
Was it possible that science could recreate the weather condition on the day of the accident?
Attorney Doug Fees wanted to know if the thick dense fog on the morning of the accident had been produced naturally or
was caused by one or more of the local industries or some combination of both. To find out, he hired Dr. Alan
Eschinrotor who teaches civil engineering at Harvard University. His area of expertise is risk management and
he also runs a consulting firm which specializes in air quality modeling. Eshenroer gathered weather information
about the morning of the accident from the Knoxville and Chattanooga airports as well as from two nuclear power
plants, one only 18 miles from the scene. Weather records indicated that there were few if any clouds on the
morning of the accident. Winds were light and the temperature dropped rapidly the night before from a high of
60° in the afternoon to almost freezing. This 30° drop in temperature could cause
a weather phenomenon called an inversion. An inversion occurs when the temperature on the ground is cooler than
the temperature in the atmosphere. This prevents air and moisture from dissipating into the atmosphere, pushing
the moisture back towards the ground. Very early on the morning of the accident, a helicopter pilot flying over
Interstate 75 noticed a mushroomshaped cloud similar to this one over the Bowwater paper mill smoke stacks 3 mi
east of the accident site. Echinroder believes this was visual confirmation of the inversion. Water vapor is produced
naturally coming from evaporation from lakes, streams, rivers and ground moisture. Dr. Esshinroer calculated that
the evaporation rate of the natural bodies of water in the area was only 392 gall per day. This was barely enough to
create even a light fog, let alone the dense, thick fog described by accident victims and rescue personnel. Echinrotor
was convinced there had to be another source of water vapor which caused the thick fog. He noticed a series of ponds
which straddled the interstate highway on two sides. These were wastewater treatment ponds which belonged to the
Bowwater paper plant. These ponds were used to clean the industrial waste water from the paper mill. In two of the
ponds, air raator fans would propel the water up into the air. Most of the water
dropped back into the ponds. Some of it did not. >> That's called drift. Drift droplets are
things that drift away from the site of where they are formed. All the other droplets fall back to earth or fall back
to the pond where they originate. So we had to do some original calculations in an engineering estimate fashion for
emission of those droplets. >> Rotor calculated that these wastewater treatment ponds added 10 million gallons
of water vapor into the atmosphere in the 24 hours preceding the accident. far more than the 392 gall from the natural
bodies of water. At the paper plant itself, an additional 1.5 million gallons of water vapor was being
released each day from the smoke stacks. But it wasn't just water vapor that was
being released from these smoke stacks. Paper plants released what are called particullet as waste from the paper
production process. Particulates are microscopic particles which become surfaces on which water vapor can
condense and this leads to fog. You not only had the fog potential from the presence of the water vapor, but you had
a place for it to form in the surfaces of these microparticles, these condensation nuclei. But how could
Echinrotor tell if the water vapor from the Bowwater paper plant 3 miles away caused the fog on the interstate highway
on the day of the accident? He found part of the answer on this aerial videotape shot by a local videographer a
few hours after the accident. Echinroer recognized the wind pattern as a drainage flow which carries cooler air
down into the valley. But Eschinroer needed to know in which direction the drainage flow was heading. To do that,
he needed to know the exact position of the airplane. Using navigational charts,
calculating the position of the sun from the glint angle off the wing and ground
references, he identified the plane's position relative to the paper mill and the accident site. The videotape
convinced Ashen Rotor that the drainage flow wind pattern was headed west from the location of the paper mill towards
the accident site. >> As to the cause of that accident that day, there's no doubt in my mind that
the industrial fog created by water emissions from that bowwater paper mill was a major factor, the major factor,
preponderantly major factor in forming the fog that caused the accident. Attorney Doug Fees now had scientific
evidence and proceeded with the civil suit he filed earlier against the Bowwater Paper Company and the state of
Tennessee. As Mike Curtis drove onto Interstate 75 on the morning of the accident, the sun
was so strong he took his jacket off in the car. When Curtis approached the fog zone, the fog warning lights in one
direction weren't working, and those in the other direction had been blinking continuously for 3 days and were
ignored. The daily police fog patrols had been abandoned years earlier. Once in the
thick fog, visibility was near zero. Mike Curtis never saw what he hit. Curtis heard crashes, people crying for
help, the explosions. >> I knelt down and asked God to help me to get through it.
>> He helped a young boy caught inside a motor home. >> Uh 12 or 13 year old boy that I got out.
His mother was inside screaming. The adrenaline was pumping and I ripped the window out and got her out. After saving
the boy and his mother, Curtis tried to save the father, but he burned to death.
There was also tragedy for a woman driving with her granddaughter. This is all that was left of the car.
This car was smashed completely flat like an accordion. >> The car was compacted down to something
in the neighborhood of 30 in long. By some miracle, this little girl lived through the entire thing.
>> The grandmother died. Randall McKeon and his two children also suffered a loss that day. They lost a
wife and mother when Judith McKon burned to death in the accident. There wasn't no body. She was over 90% gone. It was
like she had been cremated and uh there wasn't nothing to view. She still had remains, ashes,
which I'm not saying could be identified, but still knowing that she died in that
vehicle, I uh did the best I could to get everything of all the ashes out and I spread them
across that field right out there. And uh I I just I guess that was uh the only thing I knew to do.
Doug Fee's case was set for trial in 1994, more than 3 years after the accident. Bowwater disagreed with the
scientific calculations used in the Echinrotor study and hired its own scientific expert. Dr. George Mciel is a
meteorologist from Denver. His study concluded that Bowwater's contribution to the fog on the day of the accident
was less than 1%. Our conclusion was that the fog formed by a natural process due to mixing of moist air at different
altitudes at about 9:00 on the morning of December 11th after the sun had come up and heated the ground enough to start
the mixing process. And that in in a very abbreviated and simplified form is what caused the fog on that morning.
>> But shortly before the trial, the courts ordered Bowwater to release a study. it
commissioned in 1979 from its own consulting firm environmental research and technology.
In it, ERT states that preliminary evidence suggests that bowwater operations contribute to local vapor
flux and fogging problems in the Calhoun area. Doug Fees never got the chance to
prove his case in court. Before the trial, the state of Tennessee reached an outofc court settlement with
fees on behalf of the families he represented. Because of the malfunctioning fog warning system, the
state settled for $800,000 and also agreed to install a $4 million computerized fog detection system. When
the fog reaches a certain density, large signs automatically notify drivers of fog in the area and sensors trigger
gates on key entrance ramps closing access to the highway. Bowwater also settled out of court with
30 victims and families represented by Doug fees and other attorneys for $1 million. Bowwater continues to maintain
that the paper mill and treatment ponds had nothing to do with the fog on the day of the accident. However, Bowwater
agreed to limit its use of treatment pond number four, which sits near the highway.
>> But the issue isn't whether or not pond 4 is a contributor to fog, whether natural water conditions that are in the
community are contributors to fog. The real point is that fog exists in that particular place from time to time. It's
natural fog and the traffic control mechanisms on the highway have to be sufficient to warn motorists.
>> Despite the settlement and the new fog warning system, many still believe the
highway is unsafe. >> Warnings are never the answer when you can do better. closure of pond 4 is not
enough to to solve the problem. The chance of this happening again has been substantially reduced, but the risk has
not been eliminated, nor has the hazard been eliminated. >> This is only the third time I've been
here. It's uh and any officer would tell you that, you know, this is a to me it's a
memorial site. That bridge is a memorial cuz a lot of people died here. Needlessly
[Music] [Music] [Applause] Good morning. [Music]

It was the single most deadly automobile accident in American history. Almost a hundred vehicles were involved, twelve people died and more than fifty people were injured. It happened along a three-mile stretch of highway known for dense, thick fog. Now in HD.

Brief Summary

The episode details the deadly 1990 I-75 accident caused by dense fog linked to local industrial emissions.

Key points

The Deadliest Automobile Accident. The single most deadly automobile accident in American history occurred on December 11, 1990, resulting in 12 deaths and over 50 injuries.
The Fog's Mysterious Cause. Families of the victims demanded answers about the dense fog that caused the tragic accident.
Legal Battles and Settlements. After years of legal battles, settlements were reached with victims' families and improvements were made to highway safety.

Episode highlights

Episode quotes

I felt like I was in a war zone.

0:07WatchSep 19, 2025

Tension

75/ 100High tension

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