PRELIMINARY REPORT, HIGHWAY HWY15MH009
The information in this report is preliminary and will be supplemented or corrected during the course of the investigation.
About 7:10 p.m. E.D.T.
on Thursday, June 25, 2015, a 2007 Peterbilt tractor in combination with a 2005 Great Dane refrigerated semitrailer, occupied by a 39-year-old driver
and a 38-year-old passenger, was traveling
northbound on Interstate 75 (I-75) in the center lane of the three lane roadway within a highway work zone.
The weather was clear, and the roadway
was dry. Various warning
signs were placed in advance
of the work zone to alert motorists
of the on-going construction, and the posted speed limit within the work zone was 60 mph. As the combination vehicle approached milepost 11.7, traffic
was stopped in the left lane and moving
slowly in the center and right lanes due to the construction and associated lane closure ahead at milepost 12.
The combination vehicle struck the rear of a 2010 Toyota Prius passenger car located
at the end of the traffic
queue and continued moving forward while colliding
with seven other vehicles.
These other vehicles
were identified as 1) a 2010 Scion,
2) a 2003 Mazda,
3) a 2005 GMC van, 4) a 2001 Ford pickup, 5) a 2007 Chevy minivan,
6) a 2014 Cadillac,
and 7) a 2015 Toyota pickup. The Scion was occupied by a driver and three passengers; as a result of the crash, the driver was ejected, and a postcrash
fire consumed the vehicle.
The Mazda was occupied solely by the driver; it became lodged on the front of the combination vehicle and was involved
in subsequent impacts.
The combination vehicle traveled 453 feet from the initial area of impact to its final rest position.
Figure 1 shows the approach
to the crash scene and the tire marks
from various impact events.
Figure 1.
Tire marks following initial
impact event and leading to subsequent
impacts (Source – Chattanooga DOT).
As a result of the crash and postcrash
fire, the driver of the Toyota Prius, the four occupants in the Scion, and the driver of the Mazda were fatally injured.
Four other vehicle occupants sustained injuries, and eight occupants were uninjured. Figure 2 shows the combination
vehicle after it was removed from the crash scene.
Figure 2. Postcrash
damage to the 2007 Peterbilt truck-tractor.
The driver of the combination vehicle began his trip on Monday, June 22, reporting for duty in London, Kentucky. From there, he planned to pick up a load in Kentucky
and
transport it to
a location in Florida. During
this time, the driver experienced two mechanical breakdowns and was involved
in a crash with another commercial vehicle. The initial mechanical issue occurred
when he picked up the load in Kentucky
and found that his vehicle’s air compressor was unable to generate
sufficient air supply to properly operate the brake system.
The compressor was temporarily
fixed to allow the driver to return to London, where the vehicle
was taken to a repair facility and the problem with the air compressor was corrected and other maintenance items were also taken care of. Shortly after his departure from the repair facility, the driver returned
to the shop when the vehicle’s performance was found to be abnormal.
Personnel at the shop diagnosed the problem,
repaired the engine’s
fuel delivery system, and returned
the truck to the driver.
The driver did not experience any additional mechanical issues while en-route to Florida. After being on-duty for about 45 hours.,
he was involved in a crash where he side-swiped another commercial motor vehicle in Wildwood, Florida, and was subsequently cited for the traffic violation causing the crash.
No injuries were reported from this crash, but the resulting
damage to the combination vehicle caused the driver to be delayed for an additional 3 to 4 hours until the vehicle could be sufficiently repaired to continue
on the trip. The driver arrived at his final destination in Florida
on Wednesday, June 24, and after being
on duty for about 50 consecutive hours he logged himself as off-duty at 4:30 p.m.
The driver began his return
trip to London,
Kentucky, on Thursday,
June 25, about 4:30 a.m., and at 7:10 p.m., he was involved in the crash that ultimately
killed six. At this point in the investigation, it has been determined that the driver had exceeded
the Federal Motor Carrier Safety
Regulations hours-of-service when the
crash occurred.
Other aspects of the investigation are ongoing,
including a review
of various vehicle
electronic control modules
and security video that was obtained from local businesses near the crash location.
Additionally, investigators continue
to interview pertinent
witnesses and gather
other factual information concerning cell phone records,
motor carrier operations, and toxicology testing.