What Led to the Crash Involving a Jackknifed Semi on I-44 in St. Louis?

Michael GrossmanJanuary 15, 2025 2 minutes

A fatal crash involving a jackknifed semi-truck and another vehicle early Wednesday morning left one person dead and caused significant disruptions on Interstate 44 near Vandeventer Avenue. According to the Missouri Department of Transportation, the crash occurred around 6 a.m., blocking multiple eastbound lanes and leaving only one lane open to traffic.

Details remain limited, and investigators are working to reconstruct the crash to determine what happened. For me, this crash raises several questions about the operation and maintenance of the semi involved. 

What Caused the Semi to Jackknife?

Jackknifing occurs when a semi-truck’s trailer swings out of alignment with the cab, often leading to loss of control. Investigators will need to assess whether this incident was caused by mechanical failure, improper braking, or a sudden maneuver by the driver.

One common cause of jackknifing is a failure in the braking system. Uneven or poorly maintained brakes can cause a trailer to lose stability during sudden stops. Investigators should review the truck’s maintenance records to determine whether its braking system was in proper working order.

Was the Semi-Truck Operating Safely for the Conditions?

Another important question is whether the truck driver was operating the vehicle safely given the conditions at the time. Factors such as speed, following distance, and driver attentiveness will be key to understanding whether the crash could have been avoided.

The semi-truck’s Engine Control Module (ECM) can provide data on speed and braking activity leading up to the crash. Investigators will also want to determine whether the driver had sufficient training to handle sudden emergencies, as improper reactions can worsen already dangerous situations.

What Evidence Should Be Looked At?

To get a complete picture of this crash, investigators should gather data from the truck’s ECM and inspect the trailer’s condition, including its tires, brakes, and load distribution.

Traffic cameras or witness statements could also provide more information about how the truck jackknifed. Given the limited details in the initial report, this evidence will be critical in understanding what happened.

Why Semi-Truck Crashes Require Thorough Investigation

Semi-trucks play a vital role in commerce, but their size and weight mean that any mechanical failure or driver error can have serious consequences. Determining whether this jackknife incident was caused by mechanical issues, driver actions, or a combination of factors is essential for providing clarity and accountability.

In my experience, a proper investigation often reveals details that weren’t obvious immediately following the accident. This is why it’s important for the investigation to be thorough, even if the cause seems obvious.