A serious 18-wheeler accident occurred on March 13, 2026 on Interstate 35 near downtown San Antonio, leaving four people hospitalized after a chain-reaction collision involving multiple commercial vehicles and passenger vehicles. Authorities say the crash involved four vehicles and forced temporary closures and detours along the busy highway interchange connecting I-35 South to I-37 South.
San Antonio Police Department officers responded to the crash scene at approximately 9:14 a.m. Friday after reports of a major collision at the I-35 South exit ramp to I-37 South. According to police, the crash began when a box truck rear-ended a big rig. The force of the impact reportedly caused the tractor-trailer to catch fire and collide with a pickup truck towing a trailer. That pickup truck then struck a fourth vehicle, a passenger car carrying three occupants.
Emergency crews transported four people to a San Antonio hospital following the crash. Authorities said the drivers of the pickup truck, the big rig, and the box truck were all taken for medical treatment, along with a passenger in the box truck. Police reported that the 20-year-old driver of the box truck suffered serious injuries.
The crash shut down the ramp connecting I-35 South to I-37 South for several hours while emergency crews responded and investigators examined the scene. Officials say the cause of the crash remains under investigation.
Chain-Reaction Collisions on Busy Texas Highways
Highway crashes involving multiple commercial vehicles can escalate rapidly, particularly in high-traffic areas such as the interstate corridors around downtown San Antonio. When large trucks collide at highway speeds, the force of the initial impact can trigger a series of secondary collisions involving nearby vehicles.
In this case, the crash sequence reportedly began when a box truck struck the rear of a tractor-trailer. Rear-end collisions involving large trucks are especially dangerous because the initial impact can push vehicles into surrounding lanes or other traffic.
The size and weight of commercial vehicles mean that collisions often result in serious and catastrophic injuries. A fully loaded tractor-trailer can weigh up to 80,000 pounds, while most passenger vehicles weigh only a fraction of that amount.
When such vehicles collide on crowded highways, chain reactions can involve several vehicles within seconds.
Fire Risk in Commercial Truck Collisions
Authorities reported that the tractor-trailer caught fire following the initial collision. Fires after a crash can occur when fuel systems rupture or when damaged vehicles ignite due to sparks or hot engine components.
Truck fires are particularly dangerous because commercial vehicles often carry large quantities of diesel fuel. When a fire develops after a collision, occupants may have only moments to escape the vehicle before flames spread.
Emergency responders must often work quickly to extinguish fires while simultaneously rescuing injured occupants and securing the crash scene.
Investigating the San Antonio Highway Crash
The San Antonio Police Department confirmed that the information released so far is preliminary and may change as the investigation continues.
Investigators typically begin by documenting the scene and preparing an official accident report. Officers record vehicle positions, roadway conditions, and witness statements while collecting evidence that may help explain how the crash occurred.
However, serious trucking crashes often require a deeper investigation beyond the initial report. Specialists may conduct a detailed crash reconstruction to determine how each vehicle moved during the collision.
Reconstruction experts analyze skid marks, vehicle damage patterns, debris fields, and electronic data from vehicles to estimate speed, braking, and driver reaction times.
Investigators may also review surveillance footage, dash camera recordings, and statements from drivers and witnesses.
Driver Fatigue and Commercial Truck Safety Rules
One of the most common factors examined after a commercial truck crash is driver fatigue. Long driving hours can impair a driver’s alertness and reaction time, increasing the likelihood of a crash.
Federal hours of service regulations limit how long commercial drivers can operate before taking mandatory rest breaks. These rules are designed to reduce fatigue-related crashes.
Investigators may examine driver logs and electronic records from the truck’s electronic logging device to determine whether the driver had exceeded legal driving limits.
When drivers experience driver fatigue, they may fail to notice slowing traffic or may react too slowly to avoid a collision.
Vehicle Maintenance and Equipment Failures
Mechanical problems can also contribute to serious truck crashes. Large commercial vehicles rely on complex braking systems, steering components, tires, and suspension systems.
Investigators may review maintenance records to determine whether the vehicles involved in the crash were properly inspected and maintained. Commercial drivers are required to complete a pre-trip inspection before beginning their route to identify potential safety hazards.
If equipment problems or inadequate maintenance contributed to the crash, responsibility may extend beyond the driver to the trucking company responsible for maintaining the vehicle.
Brake failures, tire blowouts, and steering problems can all cause sudden loss of control on highways where vehicles are traveling at high speeds.
Injuries Common in Multi-Vehicle Truck Crashes
Victims involved in truck crashes frequently suffer severe injuries because of the violent forces generated during impact.
Some of the most serious injuries in trucking collisions include traumatic brain injury, which can result from head impacts during the crash. Victims may also suffer spinal cord injuries that affect mobility and long-term health.
Other injuries may include fractures, internal organ damage, and severe internal bleeding resulting from blunt force trauma.
Even when victims initially appear stable, medical professionals often monitor crash victims closely because some injuries can worsen over time.
Legal Claims After a Truck Crash
Crashes involving commercial trucks can create complex legal cases because multiple parties may share responsibility for the incident. Investigators must determine whether driver negligence, equipment failures, or unsafe trucking practices contributed to the crash.
Victims injured in truck collisions may pursue personal injury claims to recover compensation for medical treatment, lost income, and the long-term effects of their injuries.
Potential compensation may include economic damages for medical bills and financial losses as well as non-economic damages for pain, suffering, and reduced quality of life.
These cases often require extensive investigation, expert testimony, and analysis of trucking company records.
Contact Spagnoletti Law Firm
Truck crashes involving commercial vehicles can leave victims facing serious injuries, expensive medical treatment, and long recovery periods. Determining what caused the collision often requires a detailed investigation of driver conduct, vehicle maintenance records, and trucking company practices.
Spagnoletti Law Firm represents victims of serious truck accidents throughout Texas. Our attorneys investigate commercial vehicle crashes and pursue claims when negligent driving, unsafe trucking practices, or defective equipment contribute to catastrophic injuries.
Our firm handles these cases on a contingency fee basis and offers a free consultation to discuss your legal options.
If you or a loved one has been injured in a trucking collision, contact Spagnoletti Law Firm at 713-804-9306 or contact us online to speak with a truck accident attorney about your potential case.