(gentle music) (fire cracking)
(air whooshing)
(electronic chiming)
- [Narrator] What you're about to see are the events
that led to one fatality on the Mack Lake Fire
on May 5th, 1980.
The Mack Lake Fire burned on the Mio Ranger District
of the Huron-Manistee National Forest
located in the lower peninsula of Michigan.
The fire was an escaped prescribed burn that spread over
20,000 acres in six hours.
In addition to the firefighter fatality,
44 homes were destroyed.
Much of this area is dominated by jack pine.
Live fuel moisture in jack pine is a contributing factor
to most of the large fires that have occurred in Michigan.
Live fuel moistures drop in early May
as the jack pines concentrate all available moisture
into the new growth.
This new growth is covered with a waxy coating
that is very flammable.
Live fuel moistures on the day of the fire
were estimated to be about 105%,
which is low enough to sustain a crown fire.
The topography in the area of the fire
is comprised of gently rolling hills.
There is a significant intermix of developed subdivisions
within the forest boundaries.
Weather observations at 1045 hours on the morning
of the fire were temperature, 82 degrees, relative humidity,
34%, wind, southwest at eight to 12 miles per hour.
In the forest wide morning fire weather forecast,
a cold front passage was predicted for that afternoon
at about 1500.
This incident began as the Crane Lake prescribed burn,
which was intended to reduce logging slash
and regenerate a new jack pine stand for wildlife habitat.
Prior to the ignition of the burn,
wind and relative humidity factors
were outside of prescription.
Several of the resources identified in the burn plan
were not onsite and no spot weather forecast was requested.
However, pressure to accomplish district reforestation
targets swayed the decision to go ahead with the burn.
The plan was to start the burn at about 0900
and have the 70 acre unit completely burned by 1200.
Then, some of the personnel on the burn could be moved
into standby status to cover the higher fire dangers
that would accompany the cold front passage that afternoon.
The district had been stripped of any contingency resources
because a number of red carded individuals
were in a training session that day.
Although slash burning had been conducted in jack pine
for many years on the forest, several of the individuals
on this burn were new firefighters that had limited
experience with jack pine fuels and the equipment
they were operating.
At 1026 hours, the Crane Lake prescribed burn
was ignited at the south end of the unit.
By 1115, three spot fires had developed in grass
fuels along the southeast side of the burn.
They were quickly suppressed by the Mio District
tractor plow and the district 1000 gallon engine.
As ignition continued,
three more spot fires occurred in the grass fuels.
These were also suppressed by the tractor plow and engine.
At 1206, a seventh spot fire occurred
in an area of mature timber,
located between the burn unit and highway 33.
This area was a green strip left for aesthetic purposes.
At this time, ignition operations were shut down
and the fire crews went into a suppression mode.
The tractor plow began to build line east,
followed by the engine, trying to tie the escape
back into highway 33.
Here, you can see where the actual plow line was put in.
The tractor plow operator was a second year firefighter,
and in his first year as a tractor plow operator.
The engine was a new piece of equipment and the operators
were new forester trainees who were not experienced
with using the equipment.
You're looking south down highway 33,
the burn unit is on the right.
At 1215, the fire spotted across highway 33.
The wind had shifted to west and increased to 20 miles
per hour as the cold front approached
the area sooner than was expected.
A sharp drop in relative humidity accompanied
the frontal wind shift.
This spot fire grew to three quarters of an acre
and was suppressed by the tractor plow and engine.
However, another spot fire started just to the north.
This spot began torching trees almost immediately.
The tractor began to plow the north flank of this next
spot fire, but could not get a line around it.
Radio traffic during this time
described the fire behavior as heavy, rolling black smoke.
It's highly probable that the fire had developed into a full
crown fire by this time, moving east from highway 33.
As the situation escalated,
the radio became flooded with traffic.
All fire and district radio traffic transmissions
were on the same channel.
Additionally, no aerial detection plane was available.
This left the inexperienced tractor operator and engine crew
isolated, without effective communication.
All the actions of the tractor plow unit and engine crew
from this point on were initiated without the benefit
of instructions from an experienced supervisor.
This was also about the time that personnel on the fire
realized they could no longer stop the forward spread
of the fire they had lit, and that it was headed
for heavily developed areas around Mack Lake to the east.
The tractor plow and engine again,
re-engaged the fire at approximately 1230.
They attempted a direct flanking attack north
of a power line right of way
in a stand of young dense jack pine.
The engine was following the dozer, spraying water,
in an attempt to keep fire out of the tree crowns.
The fire was intense enough that the tractor plow
could not work directly on the fire edge,
so it was decided that the engine would work in front
to cool the flames and allow the tractor to plow
the line with less heat impact.
The engine moved ahead of the tractor,
crashing through the jack pine thicket.
This is the plow line they were working at that time.
Spot fires continued to develop behind the tractor plow
and the operator began to concentrate
on catching the spots behind him.
Within minutes, the fire intensity forced the engine
to abandon suppression efforts
and they made a desperate run to the east and then north.
There was no communication between the tractor
and the engine regarding this action.
The engine and crew escaped without harm.
It should be noted that there were no other suppression
resources working the control lines
behind the tractor and engine.
Rapid fire spread from unsecured control lines
and the numerous spot fires began to threaten the location
where the tractor plow was working.
At this point, the tractor operator left
the original line and moved 75 feet to the north
and continued in a flanking attack.
He began to plow, but must have finally realized
his effort was ineffective and tried to escape,
moving away from the flank of the fire.
At approximately 1240, he abandoned the tractor
and began to run as his position was overtaken by the fire.
His body was found within 100 feet of the tractor.
Less than 30 minutes after the burn had escaped,
a firefighter was dead.
Significant horizontal role vortex activity and associated
rapid rates of spread along the fires flanks
occurred on this fire, as evidenced by the burn patterns.
At its peak, between 1230 and 1500,
this fire burned at an average rate of spread
of two miles per hour.
Spotting was occurring up to one third of a mile
ahead of the fire and a column of smoke
of up to 15,000 feet was created.
The fire was finally controlled at 24,800 acres.
This infrared satellite image
shows the final fire perimeter.
(fire crackling)
(air whooshing)
(electronic chiming)