Two stevedores died in June 2022 trying to rescue a colleague inside a bulk carrier's cargo hold in Indonesia — a hold where oxygen levels measured 0.9%, a fraction of the 19.5% minimum for safe entry. Their deaths fit a pattern the industry has documented for decades: roughly 60% of confined space fatalities involve would-be rescuers who enter hazardous atmospheres without breathing apparatus, testing, or a rescue plan.

The numbers are stark. The U.S. Bureau of Labor Statistics counts more than 100 workers killed in confined space accidents every year. A study by the International Group of Protection & Indemnity Clubs covering 2015 through 2020 found that of 83 deaths in enclosed compartments, 53% resulted from oxygen depletion. Asphyxiation remains the leading cause of death in confined spaces across all industries, and the hazard is invisible: workers often lose consciousness before realizing anything is wrong.

The Indonesian case shows how quickly an incident cascades. During coal loading operations, a stevedore entered the access space of a cargo hold by mistake — he intended to enter a different hold containing a bulldozer. He collapsed and was found unconscious at the bottom of a ladder 26 minutes later. While the carrier's crew went to fetch rescue equipment, two other stevedores entered the space unprotected. Both succumbed to the atmosphere.

The UK's Marine Accident Investigation Branch (MAIB) identified two systemic failures: the stevedores had no training on enclosed space hazards or safe rescue methods, and the access hatches to unused cargo spaces were unlocked. A survey of enclosed space accidents by InterManager points to the same recurring causes across the fleet — the risks are known, documented, and repeatedly unmitigated.

The anatomy of a rescue disaster

A laid-up mobile offshore drilling unit illustrates the same dynamic offshore. A worker descended alone into a leg to check a diesel pump used for dewatering. An electrician found him collapsed near the pump and nearly succumbed to exhaust fumes himself before raising the alarm. A third crew member went down. Then the captain, superintendent, and a fitter entered without proper safety equipment. By the time the rigging master entered with a breathing apparatus, the fitter had collapsed. The rigging master helped the captain and superintendent escape, but the first three entrants died.

The U.S. Coast Guard later described the incident as a preventable tragedy marked by a lack of training and absent safety gear. It echoes back to Piper Alpha — the July 6, 1988 North Sea platform disaster that began with a gas leak ignition and destroyed the control room, power, and alarms.

Why do rescuers keep dying? Because seeing a colleague in distress triggers an immediate, human instinct to help. In a hazardous atmosphere, an unequipped rescuer has little chance of success and a high probability of becoming the next victim. Offshore, remoteness compounds the problem: emergency response teams may be hours away, making the "golden hour" for medical treatment unachievable.

Where the hazards hide

Confined spaces exist on every vessel and platform — cargo holds, ballast tanks, fuel tanks, pump rooms, engine compartments, and, on offshore units, legs and void spaces. OSHA defines a confined space by limited entry and exit, inadequate ventilation, and a design not intended for continuous occupancy. A space becomes "permit-required" when it contains or could contain a hazardous atmosphere, engulfment materials, converging walls, or any other recognized hazard.

Three atmospheric dangers dominate. Oxygen deficiency arises from rusting, poor airflow, or gas displacement; safe levels run between 19.5% and 23.5%. Toxic atmospheres accumulate in unventilated spaces — and even benign cargo can turn lethal. In 2022, two technicians died after entering a cargo tank on a vessel that had recently carried soybean oil, overcome by hydrogen sulfide. Flammable atmospheres become hazardous when vapors reach 10% of the Lower Explosive Limit, and a single spark can trigger an explosion endangering workers well beyond the space itself.

The regulatory framework

In U.S. shipyard employment, confined space work falls under 29 CFR Part 1915, Subpart B. Unlike general industry rules, the maritime standards do not require a traditional permit-entry system; instead they mandate specifically qualified individuals and a system of evaluation, tracking, and control measures. Atmospheric testing must follow a strict order: oxygen first, then flammability, then toxicity — because oxygen deficiency causes immediate unconsciousness while flammability may only affect hot work. Spaces are designated "Not Safe for Workers" or, where oxygen suffices, "Not Safe for Workers – Not Safe for Hot Work." Hot work adjacent to spaces that have contained flammable liquids or gases requires certification by a Marine Chemist or Coast Guard-authorized person, with the certificate posted on site and kept on file three months after work concludes.

At the international level, the IMO first addressed the issue in 2011 through Resolution A.1050(27). In June 2025, the Maritime Safety Committee went further, adopting Resolution MSC.581(110) with revised and more stringent recommendations for entering enclosed spaces aboard ships.

The regulatory gap, then, is not the problem. The procedures exist. The question — raised again by MAIB findings, InterManager's survey data, and the Coast Guard's own incident assessments — is why operators and employers continue to ignore or inadequately implement them, and what systemic change will finally make confined space work as safe as the rules already intend. For shipowners and their P&I clubs, each preventable fatality carries both human and commercial cost; the tightening IMO regime signals that regulators intend to keep the pressure on.