Colorado Springs, Colo. – A welding error is being cited as the likely cause of the deadly derailment of a BNSF coal train north of Pueblo in October 2023, according to a new report from the National Transportation Safety Board (NTSB). The incident, which led to the collapse of a railway bridge over Interstate 25, tragically resulted in the death of a truck driver traveling beneath the bridge at the time.
The NTSB’s final report, released on February 12, 2025, determined that the derailment occurred after the train encountered a rail break caused by a failed thermite weld. The weld, completed in May 2023, cracked near the base of the rail, leading to the derailment. Investigators found that the failure occurred because the welder likely did not use a “compromise kit,” as required by BNSF’s standard operating procedures. A compromise kit is necessary when there is a noticeable height difference between two pieces of metal being welded together, which in this case was 3/16 of an inch above the threshold requiring its use.
While the welder, who completed the work five months prior to the derailment, was properly trained and had used the compromise kit in previous instances, he could not recall performing the specific weld that led to the break. According to the NTSB, the welder acknowledged understanding when the compromise kit should be used but did not follow the procedure on this occasion.
BNSF has since implemented new safety measures in response to the incident. The railway has introduced random audits of welds, with instructors now checking at least 10 welds per month to ensure compliance with proper welding standards. Additionally, BNSF has updated its policies to better monitor the welding process and reduce the risk of similar accidents in the future.
The derailment caused significant disruption, with the interstate closed for days as repairs were made to the collapsed bridge. The cost of track and mechanical damages has been estimated at more than $12 million. Despite the findings of the NTSB report, it remains unclear whether any individual or entity will face accountability for the tragic incident.
In total, over 600 pages of evidence were gathered by the NTSB during the investigation, including interviews with the train’s crew and welding personnel, as well as detailed analysis of the damaged rails. The NTSB has emphasized the importance of adherence to safety procedures in preventing accidents like this one, though the exact cause of the welding oversight remains under investigation.
As the NTSB continues to review the incident, the families and communities impacted by the derailment are left to grapple with its consequences, including the loss of life and the prolonged disruption to travel on one of the state’s busiest highways.
