In brief
Ten demolition workers in Hakodate City, Hokkaido, were taken to hospital after developing headaches and nausea, with local fire officials suspecting carbon monoxide poisoning. An engine‑powered high‑pressure washer was believed to have been operating at the site, prompting an investigation into the cause of the incident. All patients remained conscious and are treating for symptoms.
Ten demolition workers were taken to hospital after developing headaches and nausea on Friday at a building demolition site in Hakodate City, Hokkaido, local fire authorities reported. The 10 people, men and women aged between their teens and 60s, complained of symptoms including headaches and nausea, and were transported to hospital. Some were unable to move without assistance, but all remained conscious, the fire department said.
The incident was reported to emergency services at around 9:05 a.m. local time, when several workers fell ill while carrying out interior work at the site. Officials said the 10 people were involved in interior demolition tasks, which in this case included the removal of interior finishes and fixtures within a partially demolished building.
According to the Hakodate Fire Department, an engine‑powered high‑pressure washer was believed to have been in use at the site. The department said it was investigating the cause of the incident, suspecting possible carbon monoxide poisoning as the source of the symptoms. The fire department blamed the use of the high‑pressure washer for the possible leak of carbon monoxide, though investigators are still looking into the matter.
Investigation and Response
City officials mobilized emergency services promptly after receiving the report. The crew that responded included medical staff who administered first aid on site and arranged transportation for the ill workers. Hospitals in the area were notified, and the patients were admitted for treatment of suspected poisoning. The local authorities maintained that they would continue to monitor the health of all involved workers.
Firefighters and occupational safety inspectors entered the site to assess the potential source of the hazardous gases. The fire department conducted a walk‑through of the premises, noting the position and operation of the high‑pressure washer. They also noted the lack of ventilation in the partially demolished structure, which could have concentrated any emissions within the interior spaces where the workers were performing tasks.
Health and Safety Implications
While the patients remain conscious, their symptoms—headaches, nausea, and reduced mobility—are consistent with exposure to CO, a colorless, odorless gas known for its high toxicity. The hospital staff assessed the patients for blood carboxyhemoglobin levels, a diagnostic test used to confirm CO poisoning. The prompt response of the fire department helped prevent the situation from deteriorating further. The patient group includes a teenager who was a student, a few middle‑aged workers who had been on the job for years, and an older worker whose health history includes hypertension. Each individual’s exposure level remains unknown until test results are completed.
The incident highlights the need for proper ventilation in demolition work, especially when powered equipment that can emit carbon monoxide is used. Workers are advised to wear personal protective equipment, including respirators with CO detectors in enclosed or confined spaces. The event also demonstrates the importance of immediate medical reporting when staff exhibit symptoms of gas exposure.
Authorities remain uncertain whether the high‑pressure washer was operating improperly or whether other equipment contributed to the CO buildup. The investigation continues to identify whether the engine’s exhaust, the fuel used, or ventilation failure led to the buildup of the gas. The fire department will likely publish a detailed report once the investigation concludes, addressing the remedial measures that should be adopted by demolition sites across Hokkaido and potentially beyond.
Stakeholders in the construction industry are monitoring the outcome of the investigation closely. The event has spurred discussions among safety regulators, labor unions, and construction firms about the adequate provision of safety training on chemical hazards. A potential shortage of breathable air is a recognized challenge during interior demolition, yet the incident has prompted calls for stricter enforcement of safety protocols and more rigorous checks of equipment operating on-site.
While the investigation is still unfolding, the immediate outcome remains clear: the ten workers are receiving medical care and are stable, and the health authorities are probing the root cause of their symptoms. The incident serves as a reminder that even routine demolition work can carry hidden hazards, and that vigilance, proper equipment, and thorough investigation are essential for worker safety.
