Not every important safety lesson comes from yesterday’s headlines. While World Safety News regularly reports on current workplace incidents, some of the most valuable opportunities for learning come from revisiting major events after investigations have progressed and more information has become available.
Although the explosion at the U.S. Steel Clairton Coke Works occurred in August 2025, the findings continue to provide important reminders for any organisation undertaking maintenance, shutdowns or other non-routine work.
The purpose of the Lessons Learned series is to look beyond the immediate news cycle and examine the organisational, operational and leadership factors that contribute to serious incidents. By reflecting on these events with the benefit of hindsight, organisations can identify practical lessons that remain just as relevant today as they were on the day the incident occurred.
Executive Summary
Maintenance is one of the most important activities undertaken in any industrial workplace. It restores equipment, improves reliability, replaces worn components and helps prevent failures that could otherwise place workers at risk. Yet history repeatedly demonstrates that maintenance activities themselves can introduce significant hazards if they are not carefully planned and controlled.
In August 2025, two workers were killed and eleven others injured following an explosion at the U.S. Steel Clairton Coke Works in Pennsylvania, USA. Subsequent regulatory investigations identified numerous deficiencies relating to maintenance planning, work procedures and hazard management. Although the incident occurred within the steel industry, the lessons extend far beyond coke production. Every organisation that isolates equipment, modifies plant, performs shutdown work or returns systems to service faces similar challenges.
This article examines the broader organisational lessons arising from the incident and explores why maintenance should never be regarded as routine work.
Incident Overview
On 11 August 2025, workers were undertaking maintenance activities at the U.S. Steel Clairton Coke Works when an explosion occurred during work associated with a coke oven gas system.
Two workers tragically lost their lives and eleven others were injured.
The Occupational Safety and Health Administration (OSHA) subsequently investigated the incident and issued multiple citations, concluding that deficiencies existed in work procedures, hazard recognition and maintenance practices. At the time of writing, investigations by the U.S. Chemical Safety and Hazard Investigation Board (CSB) continue to examine the broader organisational and technical factors that contributed to the explosion.
While the final sequence of events remains under investigation, sufficient information is available to examine several organisational themes that are common to major maintenance-related incidents across many industries.
Scope and Limitations
This article has been prepared using publicly available information, including regulatory announcements, media reporting and official statements available at the time of publication. The CSB investigation remains ongoing and additional findings may become available.
Accordingly, this analysis does not attempt to determine the precise technical cause of the explosion or attribute responsibility to any individual or organisation. Instead, it considers broader organisational factors and recognised good practice relating to maintenance management, work planning and the control of major hazards.
Maintenance Changes the Risk Profile
Maintenance is often viewed as a means of reducing risk. Worn equipment is repaired, damaged components are replaced and systems are restored to a safe operating condition. While these outcomes are essential, the maintenance process itself temporarily changes the way a facility operates.
Equipment that normally contains hazardous materials may be opened. Pipework is disconnected. Safety systems may be isolated to allow testing or replacement. Temporary arrangements are introduced, and workers perform tasks that are infrequent, technically demanding and often undertaken in close proximity to hazardous energy sources.
These changes mean that the hazards encountered during maintenance are often very different from those associated with routine production. A plant that operates safely for years under normal conditions may become significantly more vulnerable while maintenance activities are underway.
Recognising this changing risk profile is one of the fundamental challenges of effective maintenance management.
Looking Beyond the Immediate Cause
Major industrial incidents are rarely explained by a single failure. Although investigations may ultimately identify a technical initiating event, the circumstances that allow an incident to develop are often rooted in decisions made long before work begins.
Maintenance work requires organisations to coordinate engineering, operations, supervision, contractors, permit systems, isolation procedures and emergency preparedness. When these elements work together effectively, maintenance can be completed safely even in high-hazard environments. When weaknesses develop across several of these areas simultaneously, however, opportunities for unexpected interactions increase significantly.
For this reason, organisations should avoid viewing maintenance incidents as isolated procedural failures. They are more often indicators of weaknesses within the broader management system.
Planning Is More Than Scheduling Work
One of the most common misconceptions surrounding maintenance is that planning simply involves deciding when work will occur.
In reality, effective maintenance planning begins by understanding how the work changes the facility’s risk profile.
Questions organisations should consider include:
- What hazardous energy will be exposed?
- What systems will be unavailable?
- What temporary conditions will exist?
- How will work activities interact?
- What could go wrong if assumptions prove incorrect?
These questions encourage organisations to move beyond task planning and towards genuine hazard anticipation.
Assumptions Can Become Hidden Hazards
Routine maintenance often creates a false sense of familiarity.
Workers may perform similar tasks dozens or even hundreds of times throughout their careers. Equipment becomes familiar, procedures become well practised and unusual conditions gradually begin to feel routine.
This familiarity can unintentionally encourage assumptions to replace verification.
A valve is assumed to be isolated.
A line is assumed to be depressurised.
A permit is assumed to reflect current conditions.
A process is assumed to remain unchanged.
Major incidents frequently occur not because these assumptions are unreasonable, but because they are never independently confirmed.
Verification remains one of the most powerful controls available to organisations undertaking maintenance work.
Maintenance Is a Team Activity
Modern industrial maintenance rarely involves one individual working alone.
Operators, engineers, maintenance personnel, contractors, supervisors and control room staff often perform interconnected activities simultaneously.
Each group may have only part of the overall picture.
Without clear communication and coordination, individually safe decisions can combine to produce unintended consequences.
Effective maintenance management therefore depends as much on communication and shared situational awareness as it does on technical competence.
Temporary Conditions Often Become the Greatest Risk
One characteristic shared by many major industrial incidents is that they occur during temporary operating conditions rather than routine production.
Temporary pipework.
Temporary isolations.
Temporary bypasses.
Temporary procedures.
Temporary staffing arrangements.
Each temporary change introduces additional complexity.
The challenge for organisations is ensuring that temporary conditions receive the same level of scrutiny as permanent plant.
Temporary should never mean lower standards.
Learning Beyond Compliance
Regulatory investigations often identify breaches of legislation or procedural deficiencies.
These findings are important, but organisations seeking genuine improvement should ask a different question.
Rather than asking:
Which regulation was breached?
They should ask:
What assumptions within our own organisation could produce similar conditions?
This shift changes maintenance from a compliance exercise into an opportunity for organisational learning.
Recommendations Applicable Across Industries
Organisations undertaking maintenance activities should consider the following good practices:
- Recognise maintenance as a high-risk operational phase requiring structured planning and leadership oversight.
- Review how maintenance activities alter the facility’s risk profile rather than focusing solely on the task itself.
- Independently verify all isolations, depressurisation activities and safety-critical controls before commencing work.
- Ensure temporary modifications, bypasses and alternative operating arrangements are formally assessed and documented.
- Confirm that permit-to-work systems accurately reflect current site conditions.
- Strengthen communication between operations, engineering, contractors and supervisors throughout maintenance activities.
- Encourage workers to question assumptions and verify conditions before relying on previous experience.
- Review emergency response arrangements for maintenance-specific hazards.
- Capture lessons learned following major maintenance activities and incorporate them into future planning.
- Periodically audit maintenance management systems to identify organisational weaknesses before incidents occur.
Key Takeaways
- Maintenance fundamentally changes how a facility operates and should be treated as a distinct high-risk activity.
- Many maintenance-related incidents result from multiple organisational weaknesses rather than a single technical failure.
- Verification is often more important than assumption, particularly where hazardous energy is involved.
- Temporary operating conditions deserve the same level of planning and oversight as normal production.
- Effective communication between all parties involved in maintenance is essential for maintaining control of risk.
- Organisations should use maintenance activities as opportunities to strengthen learning rather than simply restore equipment.
Final Thoughts
The explosion at the Clairton Coke Works serves as a reminder that maintenance is not simply about repairing equipment—it is about managing change. Every isolation, inspection, replacement and temporary modification alters the way a facility operates, often introducing hazards that are absent during normal production. Recognising these changes and responding to them systematically is fundamental to preventing major incidents.
For health and safety professionals, perhaps the most enduring lesson is that maintenance should never be viewed as routine simply because it is scheduled. It represents a period of heightened organisational complexity, where assumptions must give way to verification, communication becomes critical and leadership is measured not by how quickly work is completed, but by how effectively risks are anticipated and controlled.
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