Forensic Files - Season 2, Episode 3 - Killer Fog - Full Episode | Forensic Files

[sirens blaring] BILL DYER: I felt like I was in a war zone with the explosions,
the smell of smoke, the smell of burning flesh, people screaming. PETER THOMAS: It was the single most deadly automobile
accident in American history. 99 vehicles, most of them destroyed. 12 people died.
REPORTER: Identifiable? No. Not at all. PETER THOMAS: More than 50 were injured.
MIKE CURTIS: Total destruction. If I hadn't been there and eye witnessed it, I don't believe I could have believed.
PETER THOMAS: 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. [theme music]
[music playing] PETER THOMAS: 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 four months
after the highway opened. Three people died in a 17 car pileup. 10 were injured.
Just one month later, there was a nine car accident. Although there were no deaths, nine were injured.
During the first six 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 fog prone 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 11, 1990. [sirens blaring] WOMAN: It's a massive wreck.
Everybody's bumping into everybody. OPERATOR: I've had several reports. I've had an explosion in that area,
and they're still piling up. BILL DYER: As I rolled down the window, I could hear the cars just crashing into each, other one
after another. MIKE CURTIS: A motor home hit the front end of my truck after just seconds, after I had gotten out.
And a vehicle started hitting the back of it. I'll never forget hearing one, and he hit other cars
and just knocked them out of the way like they were nothing and came-- crashed just to the right of that motor home.
The explosion was such that it almost knocked me down. PETER THOMAS: Mike Curtis pulled this 14-year-old boy
out of the motor home then rescued the boy's mother. MIKE CURTIS: 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.
[solemn music] It was probably the hardest thing I've ever had to witness. The most helpless feeling I've ever had.
PETER THOMAS: 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. MIKE CURTIS: The vehicles that I saw,
I don't even know if you would classify them as vehicles. What normally was a pickup truck was three foot
in length, bodies still in it. PETER THOMAS: 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 11, 1990. [music playing]
PETER THOMAS: On December 11, 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. When he entered the thick, dense fog, visibility was near zero.
Within seconds, he crashed. [boom] [tires screeching] [glass shattering] [sirens blaring]
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 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 man burn alive.
PETER THOMAS: Craig Piper's mother wanted answers and hired attorney Doug Fees, who was not only a lawyer,
but also an engineer. She wanted Fees to find out what caused the terrible fog that was responsible for her son's
death. She said the two people in that car were killed and that her son had been burned alive in this tractor trailer
and was wondering if there was anything that I could do to help her. PETER THOMAS: The accident occurred along Interstate 75
at its lowest point in the valley, about a half-mile from where the interstate crosses the Hiwassee 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 low lying 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?
WAYNE T. DAVIS: On those three days, there was some amount of river fog, although it was relatively small.
On all three days, there was a very noticeable emission of fog-related water vapor
from the Bowater facility. PETER THOMAS: The Bowater Paper Company is located three 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 three-mile stretch of Interstate 75.
The system worked-- until December 11, 1990. [dramatic music] 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 11, 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?
[solemn music] PETER THOMAS: 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 Eschenroeder 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. Eschenroeder gathered weather information about the morning of the accident
from 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 degrees in the afternoon to almost freezing. This 30 degree 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 mushroom-shaped cloud similar to this one over the Bowater paper
mill smokestacks three miles east of the accident site. Eschenroeder believes this was visual confirmation
of the inversion. Water vapor is produced naturally, coming from evaporation from lakes, streams,
rivers, and ground moisture. Dr. Eschenroeder calculated that the evaporation rate
of the natural bodies of water in the area was only 392 gallons 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.
Eschenroeder 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 belong to the Bowater Paper Plant. These ponds were used to clean the industrial wastewater
from the paper mill. In two of the ponds, aerator fans would propel the water up into the air.
Most of the water dropped back into the ponds. Some of it did not. ALAN ESCHENROEDER: And that's called drift.
The 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.
PETER THOMAS: Eschenroeder 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 gallons
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 smokestacks. But it wasn't just water vapor that was being released
from these smokestacks. Paper plants released what are called particulates, 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. PETER THOMAS: But how could Eschenroeder
tell if the water vapor from the Bowater Paper Plant three 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. Eschenroeder recognized the wind pattern
as a drainage flow, which carries cooler air down into the valley. But Eschenroeder 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 Eschenroeder that the drainage flow wind pattern was headed
west from the location of the paper mill towards the accident site. ALAN ESCHENROEDER: 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 Bowater paper mill
was a major factor-- the major factor, preponderant major factor-- in forming the fog that caused the accident.
PETER THOMAS: Attorney Doug Fees now had scientific evidence and proceeded with the civil suit he filed
earlier against the Bowater Paper Company and the state of Tennessee. [music playing]
PETER THOMAS: 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 three 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. PETER THOMAS: He helped a young boy caught inside a motor home.
MIKE CURTIS: A 12 or 13-year-old boy, so I got out. His mother was inside screaming, and the adrenaline was pumping.
And I ripped the window out and got her out. PETER THOMAS: 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. OFFICER: This car was smashed completely flat
like an accordion. TOM L GRAHAM: The car was compacted down to something in the neighborhood of 30 inches long.
By some miracle, this little girl lived through the entire thing. PETER THOMAS: The grandmother died.
Randall McKeehan and his two children also suffered a loss that day. They lost a wife and mother when Judith McKeehan burned
to death in the accident. RANDALL MCKEEHAN: There wasn't no body. She was over 90% gone.
It was like she'd been cremated. And 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 did the best I could to get everything, all the ashes out,
and I spread them across that field right out there. [crying] And I just-- I guess that was the only thing I knew to do.
PETER THOMAS: Doug Fees' case was set for trial in 1994, more than three years after the accident.
Bowater disagreed with the scientific calculations used in the Eschenroeder study and hired
its own scientific expert. Dr. George McVehil is a meteorologist from Denver. His study concluded that Bowater's
contribution to the fog on the day of the accident was less than 1%. GEORGE E. MCVEHIL: Our conclusion
was that the fog formed by a natural process due to mixing of moist air at different altitudes at about 9 o'clock
on the morning of December 11, after the sun had come up and heated the ground enough
to start the mixing process. And that, in a very abbreviated and simplified form,
is what caused the fog on that morning. PETER THOMAS: But shortly before the trial,
the courts ordered Bowater 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 Bowater 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 out-of-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. Bowater also settled out of court
with 30 victims and families represented by Doug Fees and other attorneys for $11 million.
Bowater continues to maintain that the paper mill and treatment ponds had nothing to do with the fog
on the day of the accident. However, Bowater agreed to limit its use of treatment Pond Number four, which sits near the highway.
AH BARASH: 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. PETER THOMAS: 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 solve the problem. [solemn music] 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-- and any officer would tell you that,
you know, this is a-- to me, it's a memorial site. That bridge is a memorial because a lot of people
died here, needlessly. [music playing]

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 long known for dense, thick fog. Investigators set out to determine if the fog was a natural phenomenon, or the result of something else. Originally aired as Season 2, Episode 3.

Forensic Files is the longest-running true crime series in television history. Evidence and interviews with experts help solve real crimes, disease outbreaks and accidents around the world.

Brief Summary

The episode recounts the 1990 I-75 accident, its causes, and the aftermath involving legal battles over fog-related safety.

Key points

The Deadliest Accident in History. The single most deadly automobile accident in American history involved 99 vehicles and 12 fatalities.
The Fog's Deadly Role. The dense fog that caused the accident had a history of creating dangerous conditions on the highway.
Scientific Investigation. Attorney Doug Fees hired a scientist to determine the cause of the fog on the day of the accident.
Settlement After Tragedy. The state of Tennessee settled for $800,000 due to the malfunctioning fog warning system.

Episode highlights

Episode quotes

I felt like I was in a war zone with the explosions.

BILL DYER recalls the chaos of the accident.

0:06WatchMay 27, 2021

Tension

75/ 100High tension

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